[pre-commit.ci] pre-commit autoupdate (aio-libs#6077)

updates:
- [github.com/PyCQA/flake8: 3.9.2 → 4.0.1](PyCQA/flake8@3.9.2...4.0.1)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.pre-commit-config.yaml

@@ -65,7 +65,7 @@ repos:
   - id: pyupgrade
     args: ['--py36-plus']
 - repo: https://github.com/PyCQA/flake8
-  rev: '3.9.2'
+  rev: '4.0.1'
   hooks:
   - id: flake8
     exclude: "^docs/"