Tests: Fix Preact React version expectation

[obvious-autobuild]

Closes #

What I did

Preact sandboxes resolve React 18.3.1. Removing a condition which checks for React 16.

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

Caution

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

No additional manual testing applies: the change is covered by the e2e-sandbox daily workflow, which runs the affected test against the preact-latest--vite---typescript---dev and preact-latest--vite---javascript---dev sandboxes.

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli-storybook/src/sandbox-templates.ts

• Declare whether manual QA will be needed for this PR during the next release, through qa:needed or qa:skip

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary Release - 🚫 Not run

This PR does not have a canary release associated.

In-repo PRs: add the ci:canary label. Later pushes republish while the label remains.

Fork PRs: the label does nothing (a later push must not auto-publish). A maintainer publishes from this repository with Run workflow and the pr input. branch and sha are optional; if more than one is set, they must be the same commit. The fork author does not need to do anything.

🔗 Obvious Project · 🧵 Obvious Thread

[obvious-autobuild]

Heads-up on the failing ci/circleci: init-empty-nextjs-ts check in this PR's ci:daily run: it is pre-existing on next and unrelated to this PR's one-line test-expectation change.

Evidence (CircleCI public API):

• This PR: build 2066721 (workflow daily-generated) — the init step logged Installation of dependencies failed!, the CLI swallowed it as non-blocking and exited 0, so the storybook binary was never installed; the smoke test then failed with sh: 1: storybook: not found (exit 127).
• Bare next, before this PR: build 2066309 (workflow merged-generated, 2026-09-14T13:35Z) — same job, same failure.

This is the fresh-Next.js-app dependency-installation issue tracked by #36310 (unpinned vitest resolving to the Vitest 5 line, whose @types/node peer range conflicts with the Next.js scaffold, failing the npm install under the workflow Verdaccio registry — an error the CLI currently hides).

The addon-docs expectation change in this PR is unaffected: the job that runs it (preact-latest--vite---{typescript,javascript}---dev) is green in this run.

[obvious-autobuild]

Follow-up on the second failing check, ci/circleci: tests-unit--windows: also pre-existing on next and unrelated to this PR.

Evidence (CircleCI daily-generated workflows on bare next, before this PR):

• Sep 13 run: job failed (build 2063491) — 3 unit-test failures, including help command (the leaked No Instance(s) Available. WMIC output that Core: Dispatch locally before resolving process ancestry #36311 addresses)
• Sep 12 run: job failed (build 2062962) — same job, same failure

In this PR's run (build 2066797) the 19 failing unit tests are all in the codemods package (CRLF snapshot mismatches) and the CLI help command test. This PR's diff is a two-line deletion in code/e2e-sandbox/addon-docs.spec.ts, a Playwright spec that is not part of any unit-test workspace, so it cannot affect these tests.

Both failing CircleCI jobs fail identically on next's own nightly runs; the daily daily-generated GH check inherits those failures. The two Preact dev jobs this PR targets are green in this run.