chore(deps-dev): bump @vue/cli-plugin-babel in /frontend

Bumps [@vue/cli-plugin-babel](https://github.com/vuejs/vue-cli/tree/HEAD/packages/@vue/cli-plugin-babel) 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-babel)

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

frontend/package.json

@@ -25,7 +25,7 @@
     "vuex-router-sync": "^5.0.0"
   },
   "devDependencies": {
-    "@vue/cli-plugin-babel": "^3.8.0",
+    "@vue/cli-plugin-babel": "^3.9.0",
     "@vue/cli-plugin-eslint": "^3.8.0",
     "@vue/cli-service": "^3.8.4",
     "babel-eslint": "^10.0.2",