Bump @testing-library/react from 10.3.0 to 10.4.2 in /frontend

Bumps [@testing-library/react](https://github.com/testing-library/react-testing-library) from 10.3.0 to 10.4.2.
- [Release notes](https://github.com/testing-library/react-testing-library/releases)
- [Changelog](https://github.com/testing-library/react-testing-library/blob/master/CHANGELOG.md)
- [Commits](testing-library/react-testing-library@v10.3.0...v10.4.2)

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

Author: dependabot[bot]

frontend/package-lock.json

@@ -4,7 +4,7 @@
   "private": true,
   "dependencies": {
     "@testing-library/jest-dom": "^5.10.1",
-    "@testing-library/react": "^10.3.0",
+    "@testing-library/react": "^10.4.2",
     "@testing-library/user-event": "^12.0.7",
     "react": "^16.13.1",
     "react-dom": "^16.13.1",