ProgressBar: Adjust `ProgressBar.Item` for accessibility

[TylerJDev]

Closes https://github.com/github/primer/issues/3359

Changelog

New

Changed

• Moves aria-* attributes to ProgressBar.Item
• Marks ProgressBar.Item as role="progressbar"

Removed

Rollout strategy

• [ ] Patch release
• [x] 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

• [x] Added/updated tests
• [ ] Added/updated documentation
• [ ] Added/updated previews (Storybook)
• [ ] Changes are SSR compatible
• [x] 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[bot]]

🦋 Changeset detected

Latest commit: 8b67e6787b25af2629d490a8a2a39ba61cc284e2

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	Minor

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Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions[bot]]

size-limit report 📦

Path	Size
packages/react/dist/browser.esm.js	97.26 KB (+0.02% 🔺)
packages/react/dist/browser.umd.js	97.57 KB (+0.07% 🔺)

[github-actions[bot]]

:wave: Hi, this pull request contains changes to the source code that github/github depends on. If you are GitHub staff, we recommend testing these changes with github/github using the integration workflow. Thanks!

[primer-integration[bot]]

🟢 golden-jobs completed with status success.

[TylerJDev]

Gonna wait on https://github.com/github/github/pull/344354 before I merge this PR in so we don't get failing tests :grin:

[primer-integration[bot]]

:wave: Hi from github/github! Your integration PR is ready: https://github.com/github/github/pull/349794