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

updates:
- [github.com/psf/black: 21.9b0 → 21.12b0](https://github.com/psf/black/compare/21.9b0...21.12b0)
- [github.com/PyCQA/flake8: 3.9.2 → 4.0.1](https://github.com/PyCQA/flake8/compare/3.9.2...4.0.1)
- [github.com/asottile/pyupgrade: v2.29.0 → v2.29.1](https://github.com/asottile/pyupgrade/compare/v2.29.0...v2.29.1)
- [github.com/asottile/setup-cfg-fmt: v1.18.0 → v1.20.0](https://github.com/asottile/setup-cfg-fmt/compare/v1.18.0...v1.20.0)
- [github.com/pre-commit/mirrors-mypy: v0.910-1 → v0.920](https://github.com/pre-commit/mirrors-mypy/compare/v0.910-1...v0.920)

RonnyPfannschmidt/pytest-external-blockers