Upgrade flake8

flake8-commas is no longer maintained.

Author: dmtucker

tox.ini

@@ -89,8 +89,7 @@ commands =
 deps =
     bandit ~= 1.7.0
     black ~= 22.3.0
-    flake8 ~= 3.9.0
-    flake8-commas ~= 2.0.0
+    flake8 ~= 4.0.0
     mypy >= 0.900, < 0.910
 commands =
     black --check src setup.py tests