chore(deps)(deps): bump astro from 6.3.7 to 6.4.2 in /apps/docs

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 6.3.7 to 6.4.2.
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/astro/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/astro@6.4.2/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-version: 6.4.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

apps/docs/bun.lock

@@ -35,7 +35,7 @@
     "@astrojs/sitemap": "3.7.2",
     "@astrojs/starlight": "0.39.2",
     "@tailwindcss/vite": "4.3.0",
-    "astro": "6.3.7",
+    "astro": "6.4.2",
     "astro-mermaid": "2.0.1",
     "clsx": "2.1.1",
     "mermaid": "11.15.0",