Update nextjs monorepo to v16

Author: renovate[bot]

package.json

@@ -21,7 +21,7 @@
     "livekit-client": "^2.9.5",
     "livekit-server-sdk": "^2.14.2",
     "lodash": "^4.17.21",
-    "next": "^15.5.6",
+    "next": "^16.0.0",
     "next-plugin-preval": "^1.2.6",
     "qrcode.react": "^4.1.0",
     "react": "^19.0.0",
@@ -35,7 +35,7 @@
     "@types/react-dom": "^19.0.0",
     "autoprefixer": "^10.4.20",
     "eslint": "^9.0.0",
-    "eslint-config-next": "^15.0.0",
+    "eslint-config-next": "^16.0.0",
     "postcss": "^8.4.49",
     "prettier": "^3.4.2",
     "tailwindcss": "^3.4.18",