chore(deps): bump flake8 from 4.0.1 to 6.0.0 in /dev_requirements

Bumps [flake8](https://github.com/pycqa/flake8) from 4.0.1 to 6.0.0.
- [Release notes](https://github.com/pycqa/flake8/releases)
- [Commits](PyCQA/flake8@4.0.1...6.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

dev_requirements/linter-requirements.txt

@@ -1,7 +1,7 @@
 bandit==1.7.4
 black==22.3.0
 doc8==0.10.1
-flake8==4.0.1
+flake8==6.0.0
 flake8-bugbear==22.9.11
 flake8-docstrings==1.6.0
 flake8-print==4.0.0