chore(deps): bump astro from 5.17.1 to 6.1.5 in /frontend/landing

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 5.17.1 to 6.1.5.
- [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@6.1.5/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-version: 6.1.5
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

frontend/landing/package.json

@@ -8,6 +8,6 @@
     "preview": "astro preview"
   },
   "dependencies": {
-    "astro": "^5.17.1"
+    "astro": "^6.1.5"
   }
 }