fix: examples/buildkit-in-cluster/package.json & examples/buildkit-in-cluster/package-lock.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-EXPRESS-14157151

Author: snyk-bot

examples/buildkit-in-cluster/package-lock.json

@@ -7,7 +7,7 @@
     "start": "nodemon index.js"
   },
   "dependencies": {
-    "express": "^4.17.3",
+    "express": "^4.22.0",
     "nodemon": "^2.0.17"
   },
   "keywords": [