Bump astro from 5.18.0 to 6.1.1

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 5.18.0 to 6.1.1.
- [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@6.1.1/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-version: 6.1.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

docs-src/package.json

@@ -12,7 +12,7 @@
   },
   "dependencies": {
     "@astrojs/starlight": "^0.37.6",
-    "astro": "^5.18.0",
+    "astro": "^6.1.1",
     "shepherd.js": "workspace:*",
     "starlight-typedoc": "^0.21.5"
   },

landing/package.json

@@ -14,7 +14,7 @@
     "@astrojs/mdx": "^5.0.2",
     "@astrojs/vercel": "^9.0.4",
     "@polar-sh/astro": "^0.7.5",
-    "astro": "^5.18.0",
+    "astro": "^6.1.1",
     "shepherd.js": "workspace:*"
   },
   "devDependencies": {