Bump astro from 4.16.7 to 5.15.9

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 4.16.7 to 5.15.9.
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/astro/CHANGELOG-v4.md)
- [Commits](https://github.com/withastro/astro/commits/[email protected]/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-version: 5.15.9
  dependency-type: direct:production
...

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

Author: dependabot[bot]

package.json

@@ -25,7 +25,7 @@
     "@heroicons/react": "^2.1.3",
     "@tailwindcss/forms": "^0.5.7",
     "animate.css": "^4.1.1",
-    "astro": "^4.7.0",
+    "astro": "^5.15.9",
     "dayjs": "^1.11.12",
     "dompurify": "^3.1.7",
     "leaflet": "^1.9.4",