Build(deps-dev): Bump clean-css-cli from 5.6.2 to 5.6.3 (#39464)
Bumps [clean-css-cli](https://github.com/clean-css/clean-css-cli) from 5.6.2 to 5.6.3.
- [Changelog](https://github.com/clean-css/clean-css-cli/blob/master/History.md)
- [Commits](https://github.com/clean-css/clean-css-cli/compare/v5.6.2...v5.6.3)