fix(deps): update dependency @astrojs/starlight to ^0.31.0

Author: renovate[bot]

package.json

@@ -10,7 +10,7 @@
     "astro": "astro"
   },
   "dependencies": {
-    "@astrojs/starlight": "^0.28.0",
+    "@astrojs/starlight": "^0.31.0",
     "astro": "^4.3.4",
     "sharp": "^0.33.0"
   }