* chore(deps-dev): bump black from 21.7b0 to 21.8b0

Bumps [black](https://github.com/psf/black) from 21.7b0 to 21.8b0.
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](https://github.com/psf/black/commits)

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

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

* chore: update Black workflow

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Jérôme Deuchnord <jerome@deuchnord.fr>