Adjust focus styling input components (and considers MarkdownEditor)

[dipree]

The changes in #3965 have been rolled back because of #3997.

This PR has the same changes as before plus it adds the missing outline overwrite for the MarkdownEditor.

Changelog

• Changes the focus styling of input components such as Textarea, TextInput, TextInputWithTokens from using border and box-shadow to only use outline

Changed

• Avoid potential scrollbars overlapping the border of the Textarea component
• Remove border radius fragments of Textarea, TextInput, TextInputWithTokens and Select component when focused
• Retain the box-shadow inset on focus
• Avoid text overlapping the 1px box-shadow inset on focus when scrolling

Rollout strategy

• Patch release
• Minor release
• Major release; if selected, include a written rollout or migration plan

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
• Integration tests pass at github/github (Learn more about how to run integration tests)

Take a look at the What we look for in reviews section of the contributing guidelines for more information on how we review PRs.

[changeset-bot]

🦋 Changeset detected

Latest commit: a9b9f5b

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
dist/browser.esm.js	104.55 KB (+0.01% 🔺)
dist/browser.umd.js	105.1 KB (+0.02% 🔺)