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

updates:
- [github.com/PyCQA/isort: 5.9.1 → 5.9.3](https://github.com/PyCQA/isort/compare/5.9.1...5.9.3)
- https://github.com/python/black → https://github.com/psf/black
- [github.com/psf/black: 21.6b0 → 21.7b0](https://github.com/psf/black/compare/21.6b0...21.7b0)
- https://gitlab.com/pycqa/flake8 → https://github.com/PyCQA/flake8

nschloe/quadpy