docs(deps)(deps): bump astro from 6.3.1 to 6.4.2 in /docs (#1497)

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 6.3.1 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
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

docs/package-lock.json

@@ -15,7 +15,7 @@
   },
   "dependencies": {
     "@astrojs/starlight": "^0.39.2",
-    "astro": "^6.3.1",
+    "astro": "^6.4.2",
     "sharp": "^0.34.5"
   },
   "devDependencies": {