[pre-commit.ci] pre-commit autoupdate

[pre-commit-ci[bot]]

updates:

• github.com/psf/black: 19.10b0 → 21.4b0
• https://gitlab.com/pycqa/flake8 → https://github.com/PyCQA/flake8
• github.com/PyCQA/flake8: 3.8.4 → 3.9.1
• https://github.com/timothycrosley/isort → https://github.com/PyCQA/isort
• github.com/PyCQA/isort: 5.7.0 → 5.8.0