Bump black from 21.5b1 to 21.5b2 (#5236)

Bumps [black](https://github.com/psf/black) from 21.5b1 to 21.5b2.
- [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)

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

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

dev-requirements.txt

@@ -7,7 +7,7 @@ flake8
 mypy==0.812
 
 # Automatic code formatting
-black==21.5b1
+black==21.5b2
 
 # Allows generation of coverage reports with pytest.
 pytest-cov