Update dependency @opennextjs/cloudflare to v1.15.0

Author: renovate[bot]

package.json

@@ -14,7 +14,7 @@
     "publish": true
   },
   "dependencies": {
-    "@opennextjs/cloudflare": "1.3.1",
+    "@opennextjs/cloudflare": "1.15.0",
     "next": "15.4.5",
     "react": "19.1.0",
     "react-dom": "19.1.0"