[7.x] Slim down core bundle (#75912)

[joshdover]

Backports the following commits to 7.x:

• Slim down core bundle (Slim down core bundle #75912)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 241ff92

Metrics [docs]

@kbn/optimizer bundle module count

id	value	diff	baseline
core	434	-127	561

async chunks size

id	value	diff	baseline
core	152.8KB	+152.8KB	0.0B

distributable file count

id	value	diff	baseline
default	47536	+3	47533
oss	28249	+3	28246

page load bundle size

id	value	diff	baseline
core	803.5KB	-283.7KB	1.1MB

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream