Update dependency next to v16

Author: renovate[bot]

package.json

@@ -18,7 +18,7 @@
     "dotenv-safe": "9.1.0",
     "jsdom": "27.2.0",
     "ley": "0.8.1",
-    "next": "15.5.7",
+    "next": "16.0.7",
     "postgres": "3.4.7",
     "react": "19.2.1",
     "react-dom": "19.2.1",