* [pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/psf/black: 21.9b0 → 21.10b0](https://github.com/psf/black/compare/21.9b0...21.10b0)

* Update blacken-docs too

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>