Bump @testing-library/user-event from 8.0.3 to 8.0.4 in /ui

Bumps [@testing-library/user-event](https://github.com/testing-library/user-event) from 8.0.3 to 8.0.4.
- [Release notes](https://github.com/testing-library/user-event/releases)
- [Commits](https://github.com/testing-library/user-event/compare/v8.0.3...v8.0.4)

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

ui/package.json

@@ -5,7 +5,7 @@
   "dependencies": {
     "@testing-library/jest-dom": "^5.0.0",
     "@testing-library/react": "^9.3.2",
-    "@testing-library/user-event": "^8.0.3",
+    "@testing-library/user-event": "^8.0.4",
     "jwt-decode": "^2.2.0",
     "prop-types": "^15.7.2",
     "ra-data-json-server": "^3.1.3",