Fix flake8 config in pre-commit

was missing the flake8-bugbear dependency, making effectively the
line-too-long check disabled.

.pre-commit-config.yaml

@@ -10,6 +10,7 @@ repos:
   rev: 5.0.4
   hooks:
   - id: flake8
+    additional_dependencies: [flake8-bugbear==22.9.23]
 
 - repo: https://github.com/codespell-project/codespell
   rev: v2.2.2