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>

setup.py

@@ -6,7 +6,7 @@
     "yaml": ["PyYAML>=3.10"],
     "validation": ["prance[osv]>=0.11"],
     "lint": [
-        "flake8==4.0.1",
+        "flake8==5.0.4",
         "flake8-bugbear==22.7.1",
         "pre-commit~=2.4",
         "mypy==0.971",