build(deps-dev): bump @testing-library/jest-dom in /ui/mantine-ui (#4652)

Bumps [@testing-library/jest-dom](https://github.com/testing-library/jest-dom) from 6.6.4 to 6.9.1.
- [Release notes](https://github.com/testing-library/jest-dom/releases)
- [Changelog](https://github.com/testing-library/jest-dom/blob/main/CHANGELOG.md)
- [Commits](testing-library/jest-dom@v6.6.4...v6.9.1)

---
updated-dependencies:
- dependency-name: "@testing-library/jest-dom"
  dependency-version: 6.9.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

ui/mantine-ui/package-lock.json

@@ -28,7 +28,7 @@
     "@eslint/js": "^9.29.0",
     "@ianvs/prettier-plugin-sort-imports": "^4.4.2",
     "@testing-library/dom": "^10.4.0",
-    "@testing-library/jest-dom": "^6.6.3",
+    "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^16.3.0",
     "@testing-library/user-event": "^14.6.1",
     "@types/node": "^24.9.2",