Steps to replicate the issue:
run flake8-mock (latest version 0.3) with flake8 version 5.0.0
What happens?:
10:47:13 [238] /src$ /src/.tox/flake8-py38/bin/flake8 --version
10:47:13 There was a critical error during execution of Flake8:
10:47:13 plugin code for `flake8-mock[flake8_mock]` does not match ^[A-Z]{1,3}[0-9]{0,3}$https://integration.wikimedia.org/ci/job/pywikibot-core-tox-docker/20271/console
Software version:
Python 3.6+ because flake8 5 is for Python 3.6+ only