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

updates:
- [github.com/asottile/pyupgrade: v2.12.0 → v2.14.0](https://github.com/asottile/pyupgrade/compare/v2.12.0...v2.14.0)
- [github.com/psf/black: 20.8b1 → 21.4b2](https://github.com/psf/black/compare/20.8b1...21.4b2)
- [github.com/PyCQA/flake8: 3.9.0 → 3.9.1](https://github.com/PyCQA/flake8/compare/3.9.0...3.9.1)

nijel/photoblog,nijel/photoblog