chore(deps-dev): bump @testing-library/jest-dom

Bumps [@testing-library/jest-dom](https://github.com/testing-library/jest-dom) from 5.16.4 to 6.4.2.
- [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@v5.16.4...v6.4.2)

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

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

Rnwood.Smtp4dev/ClientApp/package.json

@@ -17,7 +17,7 @@
     "@fortawesome/free-solid-svg-icons": "^6.1.1",
     "@fortawesome/vue-fontawesome": "^3.0.6",
     "@microsoft/signalr": "^8.0.0",
-    "@testing-library/jest-dom": "^5.15.0",
+    "@testing-library/jest-dom": "^6.4.2",
     "@testing-library/vue": "^5.9.0",
     "@types/jest": "^27.0.2",
     "@types/sanitize-html": "^2.6.2",