Update dependency eslint-config-next to v14.2.21 (#394)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package-lock.json

@@ -43,7 +43,7 @@
     "@types/react-dom": "18.3.5",
     "concurrently": "7.6.0",
     "eslint": "8.57.1",
-    "eslint-config-next": "14.2.20",
+    "eslint-config-next": "14.2.21",
     "jest": "28.1.3",
     "jest-environment-jsdom": "28.1.3",
     "jest-fetch-mock": "3.0.3",