Bump black from 21.9b0 to 21.10b0

Bumps [black](https://github.com/psf/black) from 21.9b0 to 21.10b0.
- [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:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -1,5 +1,5 @@
 -e .
-black==21.9b0; implementation_name=="cpython"
+black==21.10b0; implementation_name=="cpython"
 docutils==0.18
 flake8==4.0.1
 isort==5.9.3