chore(deps-dev): bump @vue/cli-plugin-eslint from 3.8.0 to 3.9.0… (#801)

Bumps [@vue/cli-plugin-eslint](https://github.com/vuejs/vue-cli/tree/HEAD/packages/@vue/cli-plugin-eslint) from 3.8.0 to 3.9.0.
- [Release notes](https://github.com/vuejs/vue-cli/releases)
- [Changelog](https://github.com/vuejs/vue-cli/blob/v3.9.0/CHANGELOG.md)
- [Commits](https://github.com/vuejs/vue-cli/commits/v3.9.0/packages/@vue/cli-plugin-eslint)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

frontend/package.json

@@ -26,7 +26,7 @@
   },
   "devDependencies": {
     "@vue/cli-plugin-babel": "^3.9.0",
-    "@vue/cli-plugin-eslint": "^3.8.0",
+    "@vue/cli-plugin-eslint": "^3.9.0",
     "@vue/cli-service": "^3.9.0",
     "babel-eslint": "^10.0.2",
     "eslint": "^5.16.0",