Bump @testing-library/user-event from 13.1.5 to 13.1.8 in /ui (#1082)

Bumps [@testing-library/user-event](https://github.com/testing-library/user-event) from 13.1.5 to 13.1.8.
- [Release notes](https://github.com/testing-library/user-event/releases)
- [Changelog](https://github.com/testing-library/user-event/blob/master/CHANGELOG.md)
- [Commits](https://github.com/testing-library/user-event/compare/v13.1.5...v13.1.8)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

ui/package.json

@@ -31,7 +31,7 @@
     "@testing-library/jest-dom": "^5.12.0",
     "@testing-library/react": "^11.2.6",
     "@testing-library/react-hooks": "^5.1.2",
-    "@testing-library/user-event": "^13.1.5",
+    "@testing-library/user-event": "^13.1.8",
     "css-mediaquery": "^0.1.2",
     "jest-environment-jsdom-sixteen": "^2.0.0",
     "prettier": "^2.2.1",