Removing the CSS modules feature flag from Blankslate

[jonrohan]

Closes https://github.com/github/primer/issues/3696

Changelog

Removed

Removes the feature flag from the Blankslate component to always render with CSS modules.

Rollout strategy

• Patch release
• Minor release
• Major release; if selected, include a written rollout or migration plan
• None; if selected, include a brief description as to why

Merge checklist

• Added/updated tests
• Added/updated documentation
• Added/updated previews (Storybook)
• Changes are SSR compatible
• Tested in Chrome
• Tested in Firefox
• Tested in Safari
• Tested in Edge
• (GitHub staff only) Integration tests pass at github/github (Learn more about how to run integration tests)

[changeset-bot]

🦋 Changeset detected

Latest commit: d98bf21

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@primer/react	Patch

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[github-actions]

size-limit report 📦

Path	Size
packages/react/dist/browser.esm.js	97.58 KB (0%)
packages/react/dist/browser.umd.js	97.7 KB (0%)