Update astro monorepo to v5

Author: renovate[bot]

package.json

@@ -14,8 +14,8 @@
     "format": "biome format --write ."
   },
   "dependencies": {
-    "@astrojs/mdx": "^4.3.13",
-    "@astrojs/react": "^4.4.2",
+    "@astrojs/mdx": "^5.0.0",
+    "@astrojs/react": "^5.0.0",
     "@heroicons/react": "^2.2.0",
     "@radix-ui/react-checkbox": "^1.3.2",
     "@radix-ui/react-dialog": "^1.1.14",