Fix underline behavior in Link component

[camertron]

What are you trying to accomplish?

The Primer::Beta::Link component does not render an underlined link when the underline: true argument is passed. I'm not sure why, since links are underlined by default. This PR makes the underlining explicit and stops using the primer/css .no-underline utility class. It also sets underline: false as the default, since that's the current behavior anyway, and will likely result in sweeping (and potentially unwanted) changes to dotcom.

Screenshots

Before	After

Integration

No changes necessary in production.

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.

Accessibility

• No new axe scan violation - This change does not introduce any new axe scan violations.

Underlining links when they are surrounded by other text is considered an accessibility best-practice. So, while this change does not fix any axe violations, it is more accessible and may impact teams' scorecards positively.

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: 00f67db

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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[github-actions]

⚠️ Visual differences found

Our visual comparison tests found UI differences. Please review the differences by viewing the files changed tab to ensure that the changes were intentional.

Review visual differences

[jonrohan]

🤘🏻 Lovely fix

[kintner]

@camertron This has resulted in underlines being rendered on hover when underline:false is set. Before the .no-underline class would prevent underline on hover as well.

[github-actions]

Uh oh! @kintner, the image you shared is missing helpful alt text. Check #2249 (comment).

Alt text is an invisible description that helps screen readers describe images to blind or low-vision users. If you are using markdown to display images, add your alt text inside the brackets of the markdown image.

Learn more about alt text at Basic writing and formatting syntax: images on GitHub Docs.

[lesliecdubs]

Thanks for the report @kintner! I've filed a follow-up issue to track resolution: #2277