build(deps): bump flake8-bugbear from 21.3.2 to 21.4.3

Bumps [flake8-bugbear](https://github.com/PyCQA/flake8-bugbear) from 21.3.2 to 21.4.3.
- [Release notes](https://github.com/PyCQA/flake8-bugbear/releases)
- [Commits](PyCQA/flake8-bugbear@21.3.2...21.4.3)

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

Author: dependabot-preview[bot]

linter-requirements.txt

@@ -2,5 +2,5 @@ black==21.5b2
 flake8==3.9.2
 flake8-import-order==0.18.1
 mypy==0.782
-flake8-bugbear==21.3.2
+flake8-bugbear==21.4.3
 pep8-naming==0.11.1