Bump @astrojs/starlight from 0.28.4 to 0.28.6

Bumps [@astrojs/starlight](https://github.com/withastro/starlight/tree/HEAD/packages/starlight) from 0.28.4 to 0.28.6.
- [Release notes](https://github.com/withastro/starlight/releases)
- [Changelog](https://github.com/withastro/starlight/blob/main/packages/starlight/CHANGELOG.md)
- [Commits](https://github.com/withastro/starlight/commits/@astrojs/[email protected]/packages/starlight)

---
updated-dependencies:
- dependency-name: "@astrojs/starlight"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

package.json

@@ -11,7 +11,7 @@
   },
   "dependencies": {
     "@astrojs/check": "^0.9.4",
-    "@astrojs/starlight": "^0.28.4",
+    "@astrojs/starlight": "^0.28.6",
     "astro": "^4.16.8",
     "sharp": "^0.33.5",
     "typescript": "^5.6.3"