fix(deps): update dependency @netlify/functions to v4

Author: renovate[bot]

package.json

@@ -10,7 +10,7 @@
     "dev-connector": "netlify-extension dev --connector"
   },
   "dependencies": {
-    "@netlify/functions": "^3.1.10",
+    "@netlify/functions": "^4.2.1",
     "@netlify/sdk": "^3.0.0",
     "react": "^19.0.0",
     "react-dom": "^19.0.0"