Bump karma from 6.3.17 to 6.4.0 (#555)

Bumps [karma](https://github.com/karma-runner/karma) from 6.3.17 to 6.4.0.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](karma-runner/karma@v6.3.17...v6.4.0)

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

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

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

Author: dependabot[bot]