Bump flake8 from 4.0.1 to 5.0.4

Bumps [flake8](https://github.com/pycqa/flake8) from 4.0.1 to 5.0.4.
- [Release notes](https://github.com/pycqa/flake8/releases)
- [Commits](PyCQA/flake8@4.0.1...5.0.4)

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

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

dev-requirements.txt

@@ -1,4 +1,4 @@
-flake8==4.0.1
+flake8==5.0.4
 pep8-naming==0.13.2
 WebTest==3.0.0
 ipdb==0.13.9