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

updates:
- [github.com/psf/black: 21.5b2 → 21.6b0](https://github.com/psf/black/compare/21.5b2...21.6b0)
- [github.com/asottile/pyupgrade: v2.19.1 → v2.19.4](https://github.com/asottile/pyupgrade/compare/v2.19.1...v2.19.4)

pytest-dev/pytest-xdist,nicoddemus/pytest-xdist