Fix prettier

Was magically missing from last commit.

Author: LimZiJia

frontend/package-lock.json

@@ -34,6 +34,7 @@
     "@types/jasmine": "~5.1.0",
     "angular-eslint": "18.3.1",
     "eslint": "^9.9.1",
+    "eslint-config-prettier": "^9.1.0",
     "eslint-plugin-prettier": "^5.2.1",
     "jasmine-core": "~5.2.0",
     "karma": "~6.4.0",