Bump @testing-library/react from 14.2.1 to 15.0.7 in /frontend (#516)

Bumps [@testing-library/react](https://github.com/testing-library/react-testing-library) from 14.2.1 to 15.0.7.
- [Release notes](https://github.com/testing-library/react-testing-library/releases)
- [Changelog](https://github.com/testing-library/react-testing-library/blob/main/CHANGELOG.md)
- [Commits](testing-library/react-testing-library@v14.2.1...v15.0.7)

---
updated-dependencies:
- dependency-name: "@testing-library/react"
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

frontend/package.json

@@ -14,7 +14,7 @@
     "@mui/material": "^5.15.16",
     "@mui/x-date-pickers": "^6.19.6",
     "@testing-library/jest-dom": "^6.2.0",
-    "@testing-library/react": "^14.0.0",
+    "@testing-library/react": "^15.0.7",
     "@testing-library/user-event": "^14.4.3",
     "@uiw/react-textarea-code-editor": "^3.0.2",
     "axios": "^1.4.0",