fix(Blankslate): Don't use Box to render heading when flag is enabled

[jonrohan]

I noticed that in Blankslate we were still using <Box to render the heading when the feature flag was enabled. This was needlessly sending us through the styled components codepath when we didn't need to.

Changelog

Changed

Only render the heading with the styled component when the feature flag is disabled.

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

Testing & Reviewing

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: a3f5485

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	96.27 KB (0%)
packages/react/dist/browser.umd.js	96.55 KB (0%)