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

Author: renovate[bot]

website/package.json

@@ -10,7 +10,7 @@
     "astro": "astro"
   },
   "dependencies": {
-    "@astrojs/starlight": "^0.28.0",
+    "@astrojs/starlight": "^0.31.0",
     "@expressive-code/plugin-collapsible-sections": "^0.40.0",
     "@expressive-code/plugin-line-numbers": "^0.40.0",
     "@fontsource/ibm-plex-mono": "^5.0.8",