chore(deps): update dependency astro to v5.18.1

Author: renovate[bot]

docs/package.json

@@ -13,7 +13,7 @@
     "@astrojs/starlight": "0.37.6",
     "@astrojs/starlight-tailwind": "4.0.2",
     "@tailwindcss/vite": "4.1.18",
-    "astro": "5.17.2",
+    "astro": "5.18.1",
     "class-variance-authority": "0.7.1",
     "clsx": "2.1.1",
     "sharp": "0.34.5",