Bump karma from 4.4.1 to 6.4.1

Bumps [karma](https://github.com/karma-runner/karma) from 4.4.1 to 6.4.1.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](karma-runner/karma@v4.4.1...v6.4.1)

---
updated-dependencies:
- dependency-name: karma
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

package.json

@@ -101,7 +101,7 @@
     "jasmine": "^3.9.0",
     "jasmine-core": "3.5.0",
     "jasmine-spec-reporter": "4.2.1",
-    "karma": "^4.4.1",
+    "karma": "^6.4.1",
     "karma-chrome-launcher": "3.1.0",
     "karma-coverage-istanbul-reporter": "2.1.1",
     "karma-firefox-launcher": "^2.1.1",