Upstream update: Review official Astro skill upstream update

[github-actions]

Automation detected pending upstream changes for Review official Astro skill upstream update.

• Issue key: official-astro-skill-upstream
• Affected skills: astro-developer
• Pending upstream watches: 1

Pending upstream sources:

• astro-main-head | http_document | withastro/astro main branch
  • Source: https://api.github.com/repos/withastro/astro/commits/main
  • Current value: W/"0a40cf3ea15bf0a245943b7c8dd643257b069d1df3e3e6019b6f2e6ba83cdbf2"
  • Detail: ETag W/"0a40cf3ea15bf0a245943b7c8dd643257b069d1df3e3e6019b6f2e6ba83cdbf2"

Why this matters:

• Review external-sources/vendir.lock.yml, sync external-sources/upstreams/astro via vendir, rerun scripts/import_external_catalog_sources.py, then regenerate catalog outputs and verify the imported astro-developer skill.

Suggested follow-up:

• Review the upstream release notes or documentation diff
• Update the affected files under skills/
• Update README.md if framework coverage or guidance changed
• Close this issue after the catalog has been refreshed