SelectPanel: Add example of trailing action support

[TylerJDev]

(For testing only)

Closes #

Changelog

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Rollout strategy

• [ ] Patch release
• [ ] 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

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

⚠️ No Changeset found

Latest commit: bcaf9dfae12c60d0785aff08aa2bb5de20785f48

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[github-actions[bot]]

:wave: Hi, this pull request contains changes to the source code that github/github-ui depends on. If you are GitHub staff, test these changes with github/github-ui using the integration workflow. Or, apply the integration-tests: skipped manually label to skip these checks.