build(deps): Bump astro from 5.15.5 to 5.15.9

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 5.15.5 to 5.15.9.
- [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/[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

@@ -34,7 +34,7 @@
         "@iconify-json/fa6-brands": "^1.2.6",
         "@iconify-json/mdi": "^1.2.3",
         "@plausible-analytics/tracker": "^0.4.4",
-        "astro": "^5.15.5",
+        "astro": "^5.15.9",
         "astro-compressor": "^1.2.0",
         "astro-font": "^1.1.0",
         "astro-icon": "^1.1.5",