feat(client): migrate to Gatsby v5 and React 18 (#65729)

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>

tools/client-plugins/gatsby-remark-node-identity/package.json

@@ -21,6 +21,9 @@
   "homepage": "https://github.com/freeCodeCamp/freeCodeCamp#readme",
   "author": "freeCodeCamp <team@freecodecamp.org>",
   "main": "gatsby-node.js",
+  "peerDependencies": {
+    "gatsby": "^5.0.0"
+  },
   "devDependencies": {
     "@freecodecamp/eslint-config": "workspace:*",
     "eslint": "^9.39.1"

tools/client-plugins/gatsby-source-challenges/package.json

@@ -21,6 +21,9 @@
   "homepage": "https://github.com/freeCodeCamp/freeCodeCamp#readme",
   "author": "freeCodeCamp <team@freecodecamp.org>",
   "main": "gatsby-node.js",
+  "peerDependencies": {
+    "gatsby": "^5.0.0"
+  },
   "devDependencies": {
     "@freecodecamp/eslint-config": "workspace:*",
     "@freecodecamp/curriculum": "workspace:*",