[Alpha][SelectPanel] Remove tabindex="-1" from li elements labelled as role="none"

[kendallgassner]

What are you trying to accomplish?

Axe logs a few errors on the SelectPanel component...

• Certain ARIA roles must be contained by particular parents
• Ensure elements marked as presentational are consistently ignored
• Certain ARIA roles must contain particular children

Initially I thought these violations were false positives because our markup:

<ul role="listbox">
  <li role="none">
    <button role="option"></button>

used role='none' to ignore the li element.

However, After investigating axe-core a bit, I discovered that I was in fact wrong and these violations are not a false positive. Someone asked a similar question a while back in axe-core and based on a code-owners response it seems that tabindexes (even if always set to -1) remove or negate role='none' / role='presentation'.

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Integration

List the issues that this change affects.

Closes # (type the GitHub issue number after #)

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.

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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 detected

Latest commit: 5aec4e4

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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[camertron]

TIL, thanks!