Update eslint to v4.31.0

Author: renovate-bot

frontend/package-lock.json

@@ -23,8 +23,8 @@
   },
   "devDependencies": {
     "@types/jest": "27.0.1",
-    "@typescript-eslint/eslint-plugin": "4.30.0",
-    "@typescript-eslint/parser": "4.30.0",
+    "@typescript-eslint/eslint-plugin": "4.31.0",
+    "@typescript-eslint/parser": "4.31.0",
     "@vue/cli-plugin-babel": "4.5.13",
     "@vue/cli-plugin-e2e-nightwatch": "4.5.13",
     "@vue/cli-plugin-eslint": "4.5.13",