chore(skills): Add `skill-creator` and update managed agent skills

[github-actions]

Note

The pull request "chore(skills): Add skill-creator and update managed agent skills" was created by @chargome but did not reference an issue. Therefore this issue was created for better visibility in external tools like Linear.

• Adds the official skill-creator skill from anthropics/skills for creating and optimizing agent skills. We should use this going forward with every skill. ref https://claude.com/blog/improving-skill-creator-test-measure-and-refine-agent-skills

• Update dotagents and skill-scanner skills to their latest versions.

[linear-code]

JS-1920

[github-actions]

A PR closing this issue has just been released 🚀

This issue was referenced by PR #19713, which was included in the 10.44.0 release.