build(deps): Bump flake8 from 5.0.4 to 6.0.0

Bumps [flake8](https://github.com/pycqa/flake8) from 5.0.4 to 6.0.0.
- [Release notes](https://github.com/pycqa/flake8/releases)
- [Commits](PyCQA/flake8@5.0.4...6.0.0)

---
updated-dependencies:
- dependency-name: flake8
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

tests/REQUIREMENTS.lint.txt

@@ -5,7 +5,7 @@ typing-extensions
 
 tox
 coverage
-flake8==5.0.4
+flake8==6.0.0
 flake8-2020==1.7.0
 flake8-bugbear==22.10.27
 flake8-commas==2.1.0