Add focus styles to Pagination component

[langermank]

Closes: https://github.com/github/accessibility-audits/issues/8461
Closes: https://github.com/github/accessibility-audits/issues/8056

• Updates the focus style for the current page
• Updates the focus style for all items to match

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: 81d639f

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	96.7 KB (-0.01% 🔽)
packages/react/dist/browser.umd.js	96.99 KB (-0.04% 🔽)