Bump karma from 5.0.5 to 5.0.8

Bumps [karma](https://github.com/karma-runner/karma) from 5.0.5 to 5.0.8.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](https://github.com/karma-runner/karma/compare/v5.0.5...v5.0.8)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>