Bump black from 20.8b1 to 23.7.0 in /.github/workflows

Bumps [black](https://github.com/psf/black) from 20.8b1 to 23.7.0.
- [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/23.7.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/constraints.txt

@@ -1,5 +1,5 @@
 pip==21.0
 pre-commit==2.9.3
-black==20.8b1
+black==23.7.0
 flake8==3.8.4
 reorder-python-imports==3.10.0