[CodeStyle][W605] Update .flake8 config (#46753)

* Update .flake8 config: remove W605, test=document_fix

* Resolve conflict, test=document_fix

.flake8

@@ -30,7 +30,6 @@ ignore =
 
     # W, see https://pycodestyle.pycqa.org/en/latest/intro.html#error-codes
     W503,W504
-    W605
 per-file-ignores =
     # These files need tabs for testing.
     python/paddle/fluid/tests/unittests/dygraph_to_static/test_error.py:E101,W191