remove flake8 (#2544)

.pre-commit-config.yaml

@@ -25,12 +25,6 @@ repos:
         language: system
         always_run: true
         pass_filenames: false
-      - id: flake8
-        name: flake8
-        entry: flake8 --statistics -j4
-        language: system
-        always_run: true
-        pass_filenames: false
       - id: tests
         name: subset of TORCH tests
         entry: env PYTHONPATH="." TORCH=1 python3 -m pytest -n=4 test/unit/ test/test_ops.py test/test_dtype.py test/test_schedule.py test/test_custom_function.py test/test_assign.py test/test_symbolic_shapetracker.py