fix: examples/buildkit/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-QS-14724253

Author: snyk-bot

examples/buildkit/package.json

@@ -7,7 +7,7 @@
     "start": "nodemon index.js"
   },
   "dependencies": {
-    "express": "^4.18.1",
+    "express": "^4.22.0",
     "nodemon": "^2.0.17"
   },
   "keywords": [