fix: examples/with-clerk/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-POSTCSS-5926692
- https://snyk.io/vuln/SNYK-JS-ZOD-5925617

examples/with-clerk/package.json

@@ -10,7 +10,7 @@
     "@types/node": "20.5.7",
     "@types/react": "18.2.21",
     "@types/react-dom": "18.2.7",
-    "next": "13.4.2",
+    "next": "13.5.4",
     "react": "18.2.0",
     "react-dom": "18.2.0",
     "typescript": "5.2.2"