Merge pull request #911 from twisted/dependabot/pip/flake8-pep3101-3.0.0

Bump flake8-pep3101 from 2.1.0 to 3.0.0

Author: cjwatson

requirements/flake8.txt

@@ -4,7 +4,7 @@ flake8==7.3.0
 flake8-bugbear==25.11.29
 flake8-docstrings==1.7.0
 flake8-mutable==1.2.0
-flake8-pep3101==2.1.0
+flake8-pep3101==3.0.0
 pep8-naming==0.15.1
 pycodestyle==2.14.0
 pydocstyle==6.3.0