forgot to bring back the plugin

Author: nsdeschenes

integration-tests/test-apps/nextjs/package.json

@@ -14,6 +14,7 @@
     "next": "15.0.1"
   },
   "devDependencies": {
+    "@codecov/nextjs-webpack-plugin": "workspace:^",
     "typescript": "^5",
     "@types/node": "^20",
     "@types/react": "^18",