[Snyk] Security upgrade next from 15.1.0 to 15.4.2 (CopilotKit#2393)

Co-authored-by: snyk-bot <snyk-bot@snyk.io>

Author: ataibarkai

examples/coagents-starter/ui/package.json

@@ -20,7 +20,7 @@
     "clsx": "^2.1.1",
     "framer-motion": "^11.3.31",
     "lucide-react": "^0.436.0",
-    "next": "15.1.0",
+    "next": "15.4.2",
     "openai": "^4.85.1",
     "react": "19.0.0",
     "react-dom": "19.0.0",