chore(deps-dev): bump astro from 5.14.4 to 5.15.6

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 5.14.4 to 5.15.6.
- [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: 5.15.6
  dependency-type: direct:development
...

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

Author: dependabot[bot]

apps/outreach/package.json

@@ -28,7 +28,7 @@
     "@opendatacapture/runtime-core": "workspace:*",
     "@tailwindcss/typography": "^0.5.16",
     "@tailwindcss/vite": "^4.1.5",
-    "astro": "^5.13.1",
+    "astro": "^5.15.6",
     "github-slugger": "^2.0.0",
     "sharp": "^0.33.5",
     "tailwindcss": "catalog:",