Bump flake8 from 4.0.1 to 5.0.4 (#533)

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:production
  update-type: version-update:semver-major
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements_test.txt

@@ -1,6 +1,6 @@
 black==22.6.0
 coverage==6.4.2
-flake8==4.0.1
+flake8==5.0.4
 flake8-comprehensions==3.10.0
 flake8-docstrings==1.6.0
 flake8-noqa==1.2.8