Update flake8 to 5.0.3#138

pyup-bot wants to merge 3 commits intomasterpythonprgbr/libpythonjp:masterfrom

pyup-update-flake8-3.8.4-to-5.0.3pythonprgbr/libpythonjp:pyup-update-flake8-3.8.4-to-5.0.3Copy head branch name to clipboard