fixup! Add E401

.github/workflows/lint.yml

@@ -28,5 +28,5 @@ jobs:
       - name: Lint with flake8
         run: |
           pip install flake8
-          flake8 --ignore=E126,E127,E128,E131,E226,E231,E302,E303,E305,E402,E701,E731,F401,F403,F405,W291,W292,W293,W391 \
+          flake8 --ignore=E126,E127,E128,E131,E226,E231,E302,E303,E305,E401,E402,E701,E731,F401,F403,F405,W291,W292,W293,W391 \
                  --max-complexity=32 --max-line-length=525 --show-source --statistics .