Bump astro in /docs in the npm_and_yarn group across 1 directory

Bumps the npm_and_yarn group with 1 update in the /docs directory: [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro).


Updates `astro` from 6.3.1 to 6.4.8
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/astro@6.4.8/packages/astro/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/astro@6.4.8/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-version: 6.4.8
  dependency-type: direct:production
  dependency-group: npm_and_yarn
...

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

Author: dependabot[bot]

docs/package-lock.json

@@ -11,7 +11,7 @@
   },
   "dependencies": {
     "@astrojs/starlight": "^0.38.2",
-    "astro": "^6.3.1",
+    "astro": "^6.4.8",
     "sharp": "^0.34.5"
   }
 }