ensure overlay does not add aria-label if it has no role

[keithamus]

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What are you trying to accomplish?

Fix https://github.com/github/primer/issues/2668 which notes that there is an AXE violation due to the ActionMenu <anchored-position> having no role assigned, but having an aria-label.

Screenshots

Integration

No

List the issues that this change affects.

Closes https://github.com/github/primer/issues/2668

Risk Assessment

• Low risk the change is small, highly observable, and easily rolled back.
• Medium risk changes that are isolated, reduced in scope or could impact few users. The change will not impact library availability.
• High risk changes are those that could impact customers and SLOs, low or no test coverage, low observability, or slow to rollback.

What approach did you choose and why?

I decided to guard the assignment of aria-label so that it isn't set if the :role isn't supplied.

Anything you want to highlight for special attention from reviewers?

Accessibility

• Fixes axe scan violation - This change fixes an existing axe scan violation.
• No new axe scan violation - This change does not introduce any new axe scan violations.
• New axe violation - This change introduces a new axe scan violation. Please describe why the violation cannot be resolved below.

Merge checklist

• Added/updated tests
• Added/updated documentation
• Added/updated previews (Lookbook)
• Tested in Chrome
• Tested in Firefox
• Tested in Safari
• Tested in Edge

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[changeset-bot]

🦋 Changeset detected

Latest commit: bab4b15

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

This PR includes changesets to release 1 package

Name	Type
@primer/view-components	Patch

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