Backport to 24.2: 8 cherry-picks for stable

[jorgefilipecosta]

Similar to #78927.

Currently, five PRs merged into trunk after 24.2.0 RC1 carry the Backport to Gutenberg RC label, and none of them is on release/24.2 yet.

This PR cherry-picks them onto release/24.2, so they ship in 24.2.0:

• Icons: Experiment with proportional stroke scaling #84081 Icons: Experiment with proportional stroke scaling.
• Global Styles: Ignore theme.json values of unexpected types #84523 Global Styles: Ignore theme.json values of unexpected types.
• React 19 codemod: apply defaultProps when rendering a memo component #84568 React 19 codemod: apply defaultProps when rendering a memo component.
• React 19: add new incompatible plugins #84607 React 19: add new incompatible plugins.
• Experiments: don't invalidate saved option with a legacy key #84619 Experiments: don't invalidate saved option with a legacy key.

It also cherry-picks three test-only PRs, so the tests pass on this branch. They adapt the tests to WordPress trunk changes that landed after release/24.2 was cut, so release/24.2 fails those tests even without the PRs above:

• Tests: Fix HTML comparison tests #84294 Tests: Fix HTML comparison tests, after the KSES change in https://core.trac.wordpress.org/changeset/64233.
• Tests: Fix list item unsafe markup test on older WordPress versions #84302 Tests: Fix list item unsafe markup test on older WordPress versions, a follow-up to the previous one.
• Tests: Scope Classic block media checkbox locator #84524 Tests: Scope Classic block media checkbox locator, after the media modal change in Media: Refresh attachment tile aria-label when model data loads wordpress-develop#13053.

All eight applied cleanly. Each commit has the same patch, message and author as its trunk commit, and no other trunk commit touched their files between the 24.2 branch point and their merge.

After merging, a few manual steps are needed.

1. Move the five backported PRs from the Gutenberg 24.3 milestone to Gutenberg 24.2, so the stable release notes list them. The three test-only PRs can stay in Gutenberg 24.3.
2. Remove the Backport to Gutenberg RC label from them.
3. Add Icons: Experiment with proportional stroke scaling #84081 to the 24.2.0 release notes by hand. It was merged before RC1 was published, and the release notes generator only picks PRs closed after the latest release in the series, so it skips that PR even after the milestone change.

Testing Instructions

1. Check that CI passes.
2. Check that each cherry-pick has the same patch ID as its trunk commit:

for pair in ad74c674ee7:38c67679451 4f07474d09a:e8dbcedbc96 f05c2043ceb:ea46d8e7a6a 2776a1a482a:4b875452a8f 289a6e50736:23272debf66 9355f4a55dd:0e0a3463e53 f9d12ae432e:f297a1598e8 9af2d4154e6:6dd766b8a89; do
	git show "${pair%%:*}" | git patch-id --stable
	git show "${pair##*:}" | git patch-id --stable
done

AI usage disclosure: fix and description drafted with AI assistance and reviewed by me.

[github-actions]

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Co-authored-by: ciampo <mciampini@git.wordpress.org>
Co-authored-by: ramonjd <ramonopoly@git.wordpress.org>
Co-authored-by: jsnajdr <jsnajdr@git.wordpress.org>
Co-authored-by: sirreal <jonsurrell@git.wordpress.org>

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[github-actions]

🤖 PR meta 🤖

📦 Bundle size

Size Change: -1.02 kB (-0.01%)

Total Size: 8.3 MB

📦 View Changed

Filename	Size	Change
build/modules/boot/index.min.js	57.9 kB	-28 B (-0.05%)
build/modules/edit-site-init/index.min.js	1.7 kB	-28 B (-1.62%)
build/modules/workflow/index.min.js	86.9 kB	-18 B (-0.02%)
build/scripts/block-directory/index.min.js	44.4 kB	-20 B (-0.05%)
build/scripts/block-editor/index.min.js	517 kB	-214 B (-0.04%)
build/scripts/block-library/index.min.js	367 kB	-241 B (-0.07%)
build/scripts/commands/index.min.js	21.8 kB	-21 B (-0.1%)
build/scripts/components/index.min.js	335 kB	-66 B (-0.02%)
build/scripts/core-commands/index.min.js	3.94 kB	-23 B (-0.58%)
build/scripts/core-data/index.min.js	78.9 kB	-32 B (-0.04%)
build/scripts/customize-widgets/index.min.js	59.2 kB	-44 B (-0.07%)
build/scripts/edit-post/index.min.js	53 kB	-27 B (-0.05%)
build/scripts/edit-site/index.min.js	386 kB	-109 B (-0.03%)
build/scripts/edit-widgets/index.min.js	67 kB	-42 B (-0.06%)
build/scripts/editor/index.min.js	622 kB	-109 B (-0.02%)
build/scripts/format-library/index.min.js	41.4 kB	-39 B (-0.09%)
build/scripts/media-utils/index.min.js	227 kB	-107 B (-0.05%)
build/scripts/patterns/index.min.js	12.4 kB	-21 B (-0.17%)
build/scripts/plugins/index.min.js	3.2 kB	-21 B (-0.65%)
build/scripts/preferences/index.min.js	3.33 kB	-23 B (-0.69%)
build/scripts/vendors/react-19.min.js	4.17 kB	+52 B (+1.26%)
build/scripts/vendors/react-dom-19.min.js	68 kB	+190 B (+0.28%)
build/scripts/widgets/index.min.js	7.45 kB	-28 B (-0.37%)

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⚡ Performance

Show the results

Client side metrics exclude the server response time.

front-end-block-theme

Metric	d400066	release/24.2	% Change
timeToFirstByte	55.7 ms +9.25% -2.15%	56 ms +11.87% -2.32%	-0.54%
largestContentfulPaint	96 ms +4.17% -8.33%	92 ms +4.35% -4.35%	4.35%
lcpMinusTtfb	38.8 ms +8.38% -15.85%	33.25 ms +5.56% -2.86%	16.69%
wpBeforeTemplate	27.57 ms +15.85% -1.31%	27.49 ms +16.11% -1.02%	0.29%
wpTemplate	23.98 ms +3.84% -3.25%	24.42 ms +1.88% -4.42%	-1.8%
wpTotal	52.02 ms +9.96% -1.96%	52.47 ms +11.28% -2.71%	-0.86%
wpMemoryUsage	7.67 MB +0% -0%	7.65 MB +0% -0%	0.37%
wpDbQueries	17 +0% -0%	17 +0% -0%	0%

front-end-classic-theme

Metric	d400066	release/24.2	% Change
timeToFirstByte	42.2 ms +6.04% -1.3%	47.6 ms +6.93% -3.05%	-11.34%
largestContentfulPaint	90 ms +2.22% -2.22%	100 ms +4% -0%	-10%
lcpMinusTtfb	46.85 ms +3.42% -1.07%	53.6 ms +1.4% -3.17%	-12.59%
wpBeforeTemplate	25.67 ms +5.77% -0.78%	25.8 ms +8.49% -1.36%	-0.5%
wpTemplate	13.45 ms +3.35% -1.26%	17.65 ms +4.7% -0.85%	-23.8%
wpTotal	39.43 ms +6.31% -1.32%	44.57 ms +6.98% -3.61%	-11.53%
wpMemoryUsage	6.16 MB +0% -0%	6.26 MB +0% -0%	-1.67%
wpDbQueries	10 +0% -0%	14 +0% -0%	-28.57%

media-processing

Metric	d400066	release/24.2	% Change
mediaProcessingJpeg	405.6 ms +1.14% -1.1%	399.16 ms +1.86% -0.28%	1.61%
mediaProcessingAvif	6050.57 ms +0.15% -0.17%	6032.69 ms +0.29% -0.15%	0.3%
mediaProcessingJpegToAvif	4147.34 ms +0.33% -0.09%	4149.24 ms +0.09% -0.06%	-0.05%

media-upload

Metric	d400066	release/24.2	% Change
jpegUploadProcessing	1476.9 ms +30.55% -3.13%	1415.45 ms +1.11% -0.73%	4.34%
pngUploadProcessing	218.85 ms +4.01% -16.63%	193.62 ms +14.55% -13.52%	13.03%
largeJpegUploadProcessing	1401.87 ms +0.23% -0.56%	1400.04 ms +1.06% -0.25%	0.13%
multipleImageUploadProcessing	1528.22 ms +0.18% -1.01%	1530.38 ms +0.56% -0.59%	-0.14%

post-editor

Metric	d400066	release/24.2	% Change
serverResponse	307.65 ms +5.58% -12.1%	311.66 ms +3.74% -8.53%	-1.29%
firstPaint	322.06 ms +10.13% -20.49%	331.48 ms +7.56% -14%	-2.84%
domContentLoaded	785.06 ms +1.9% -2.84%	756.59 ms +4.23% -3.78%	3.76%
loaded	786.02 ms +1.92% -2.83%	757.52 ms +4.23% -3.75%	3.76%
firstContentfulPaint	355.84 ms +1.03% -4.52%	340.86 ms +4.6% -4.63%	4.39%
firstBlock	2300.89 ms +4.13% -1.71%	2296.19 ms +2.27% -0.33%	0.2%
type	15.58 ms +11.42% -3.08%	15.81 ms +7.65% -2.97%	-1.45%
typeWithoutInspector	16.2 ms +4.32% -5.56%	16.32 ms +3.12% -2.94%	-0.74%
typeWithTopToolbar	20.5 ms +6.1% -2.83%	20.91 ms +6.74% -0.48%	-1.96%
typeContainer	7.81 ms +7.81% -3.46%	7.83 ms +1.4% -3.07%	-0.26%
focus	88.09 ms +6.12% -5.05%	86.83 ms +8.29% -8.07%	1.45%
firstFocus	155.49 ms +0% -0%	154.92 ms +0% -0%	0.37%
selectAll	340.92 ms +17.02% -0.97%	353.17 ms +0.68% -0.26%	-3.47%
listViewOpen	54.12 ms +4.07% -3.62%	55.59 ms +3.47% -0.41%	-2.64%
inserterOpen	31.63 ms +3.79% -2.5%	32.23 ms +3.29% -3.79%	-1.86%
inserterHover	10.83 ms +11.17% -7.85%	10.76 ms +6.78% -6.78%	0.65%
inserterSearch	8.24 ms +4.37% -5.34%	8.01 ms +7.37% -7.62%	2.87%
loadPatterns	503.86 ms +1.81% -7.9%	481.42 ms +7.21% -2.26%	4.66%
wpTotal	297.92 ms +5.38% -12.32%	302.39 ms +3.31% -8.84%	-1.48%
wpMemoryUsage	13.27 MB +0% -0%	13.24 MB +0% -0%	0.21%
wpDbQueries	54 +0% -0%	54 +0% -0%	0%

site-editor

Metric	d400066	release/24.2	% Change
serverResponse	406.01 ms +1.83% -10.3%	412.55 ms +2.26% -5.98%	-1.59%
firstPaint	223.91 ms +26.94% -8.3%	245.51 ms +24.52% -14.22%	-8.8%
domContentLoaded	1156.61 ms +0.63% -0.74%	1155.59 ms +0.61% -1.7%	0.09%
loaded	1157.91 ms +0.64% -0.73%	1156.96 ms +0.59% -1.69%	0.08%
firstContentfulPaint	479.74 ms +2.42% -2.3%	480.8 ms +2.81% -4.67%	-0.22%
firstBlock	4191.71 ms +0.39% -0.54%	4167.96 ms +1.65% -1.1%	0.57%
type	18.54 ms +5.18% -4.15%	19.38 ms +2.01% -4.33%	-4.33%
navigate	118.05 ms +12.1% -3.19%	114.71 ms +14.41% -2.12%	2.91%
loadPatterns	1212.25 ms +1.98% -5.41%	1127.17 ms +3.89% -3.95%	7.55%
loadPages	1072.93 ms +1.77% -1.63%	1053.75 ms +2.68% -4.3%	1.82%
wpTotal	394.35 ms +1.76% -10.57%	400.64 ms +2.25% -6.1%	-1.57%
wpMemoryUsage	12.31 MB +0% -0%	12.28 MB +0% -0%	0.26%
wpDbQueries	43 +2.33% -0%	43 +2.33% -0%	0%

_{6dd766b Run}

🏁 Flaky tests

Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

Navigates the items list via UP/DOWN arrow keys in /test/e2e/specs/site-editor/dataviews-list-layout-keyboard.spec.js, passed after 1 failed attempt.

Error: expect(locator).toBeFocused() failed

Locator:  getByLabel('Page Two')
Expected: focused
Received: inactive
Timeout:  5000ms

Call log:
  - Expect "toBeFocused" getByLabel('Page Two') with timeout 5000ms
  - waiting for getByLabel('Page Two')
    14 × locator resolved to <button type="button" tabindex="-1" aria-pressed="false" id="view-list-0-336-item-wrapper" class="dataviews-view-list__item" aria-labelledby="view-list-0-336-label" aria-describedby="view-list-0-336-description"></button>
       - unexpected value "inactive"

    at /home/runner/work/gutenberg/gutenberg/test/e2e/specs/site-editor/dataviews-list-layout-keyboard.spec.js:146:49

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