[framework-fixture-dependencies]: Bump astro

Bumps the core group with 1 update in the /packages/static-build/test/fixtures/astro-v4 directory: [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro).


Updates `astro` from 4.12.2 to 4.16.18
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/[email protected]/packages/astro/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/[email protected]/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: core
...

Signed-off-by: dependabot[bot] <[email protected]>