Bump flake8 from 3.9.1 to 3.9.2

Bumps [flake8](https://gitlab.com/pycqa/flake8) from 3.9.1 to 3.9.2.
- [Release notes](https://gitlab.com/pycqa/flake8/tags)
- [Commits](https://gitlab.com/pycqa/flake8/compare/3.9.1...3.9.2)

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

Author: dependabot[bot]

linter-requirements.txt

@@ -1,5 +1,5 @@
 bandit==1.7.0
 black==21.5b0
-flake8==3.9.1
+flake8==3.9.2
 isort==5.8.0
 pydocstyle==6.0.0