build(deps-dev): bump karma from 4.3.0 to 6.3.16

Bumps [karma](https://github.com/karma-runner/karma) from 4.3.0 to 6.3.16.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](karma-runner/karma@v4.3.0...v6.3.16)

---
updated-dependencies:
- dependency-name: karma
  dependency-type: direct:development
...

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

Author: dependabot[bot]

package.json

@@ -74,7 +74,7 @@
     "gulp-sass": "^4.1.0",
     "jasmine-core": "~3.5.0",
     "jasmine-spec-reporter": "~4.2.1",
-    "karma": "~4.3.0",
+    "karma": "~6.3.16",
     "karma-chrome-launcher": "~3.1.0",
     "karma-coverage-istanbul-reporter": "~2.1.0",
     "karma-jasmine": "~2.0.1",