Allow text wrapping in AnchorNav

[joshfarrant]

Summary

Allow AnchorNav links to reflow on narrow viewports.

I'm not sure the component is meant to support longer link names in the first place as they don't look great on desktop, but for those cases where the text might just break onto the next line this change does offer a slightly better experience.

Note that this change doesn't make the AnchorNav work perfectly with arbitrarily-long link names, but it does make it a bit more flexible.

Steps to test:

1. Modify the data of the Playground story in the AnchorNav storybook
2. Reduce the viewport width until the text reflows.

Supporting resources (related issues, external links, etc):

• Closes https://github.com/github/primer/issues/3757

Contributor checklist:

• All new and existing CI checks pass
• Tests prove that the feature works and covers both happy and unhappy paths
• Any drop in coverage, breaking changes or regressions have been documented above
• UI Changes contain new visual snapshots (generated by adding update snapshots label to the PR)
• All developer debugging and non-functional logging has been removed
• Related issues have been referenced in the PR description

Reviewer checklist:

• Check that pull request and proposed changes adhere to our contribution guidelines and code of conduct
• Check that tests prove the feature works and covers both happy and unhappy paths
• Check that there aren't other open Pull Requests for the same update/change

Screenshots:

Please try to provide before and after screenshots or videos

Before	After

[changeset-bot]

🦋 Changeset detected

Latest commit: 81e5bd4

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

This PR includes changesets to release 6 packages

Name	Type
@primer/react-brand	Patch
@primer/brand-primitives	Patch
@primer/brand-e2e	Patch
@primer/brand-fonts	Patch
@primer/brand-config	Patch
@primer/brand-storybook	Patch

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[github-actions]

🟢 No design token changes found

[github-actions]

🟢 No visual differences found

Our visual comparison tests did not find any differences in the UI.

[rezrah]

I can't remember what that 80px was originally doing, but it was probably something important 😄. Do you know @joshfarrant?

[joshfarrant]

I'm not entirely sure if I'm honest @rezrah. If you look at the snapshots you can see (by looking at the focus border) that the item was 80px narrower than you'd probably expect it to be. Maybe something in the implementation changed since this component was created which rendered that 80px no longer useful?

[rezrah]

No worries, not a blocker

[rezrah]

LGTM. Could you take a look at the snapshots again please, looks like there might be an issue there?