[SKIP CI] remove custom flake8 format

.flake8

@@ -3,4 +3,3 @@ ignore = D101, D102, D103, D105, D107, E402, W503
 max-line-length = 99
 inline-quotes = double
 exclude = .git,.tox,__pycache__,build,dist,tests,*.pyc,*.egg-info,.cache,.eggs,env*
-format = ${cyan}%(path)s:%(row)d:%(col)d${reset}: ${red_bold}%(code)s${reset} %(text)s