Bump @testing-library/jest-dom from 5.17.0 to 6.9.1 in /plugins/cad

Bumps [@testing-library/jest-dom](https://github.com/testing-library/jest-dom) from 5.17.0 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@v5.17.0...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-major
...

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

Author: dependabot[bot]

plugins/cad/package.json

@@ -55,7 +55,7 @@
     "@backstage/core-app-api": "^1.12.5",
     "@backstage/dev-utils": "^1.0.32",
     "@backstage/test-utils": "^1.5.5",
-    "@testing-library/jest-dom": "^5.10.1",
+    "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^12.1.3",
     "@testing-library/user-event": "^14.0.0",
     "@types/diff": "^5.0.2",