Bump @testing-library/user-event from 11.4.1 to 12.0.2 in /frontend

Bumps [@testing-library/user-event](https://github.com/testing-library/user-event) from 11.4.1 to 12.0.2.
- [Release notes](https://github.com/testing-library/user-event/releases)
- [Changelog](https://github.com/testing-library/user-event/blob/master/CHANGELOG.md)
- [Commits](testing-library/user-event@v11.4.1...v12.0.2)

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

Author: dependabot[bot]

frontend/package-lock.json

@@ -5,7 +5,7 @@
   "dependencies": {
     "@testing-library/jest-dom": "^5.9.0",
     "@testing-library/react": "^10.2.1",
-    "@testing-library/user-event": "^11.4.1",
+    "@testing-library/user-event": "^12.0.2",
     "react": "^16.13.1",
     "react-dom": "^16.13.1",
     "react-router-dom": "^5.2.0",