chore: upgrade @netlify/build

Author: pieh

demo-v5/package.json

@@ -21,7 +21,7 @@
   },
   "dependencies": {
     "@sindresorhus/slugify": "^1.1.2",
-    "gatsby": "next",
+    "gatsby": "5.11.0",
     "gatsby-plugin-image": "next",
     "gatsby-plugin-sharp": "next",
     "gatsby-source-filesystem": "next",