Fix Python 3.8/3.9 jobs on Ubuntu 26.04, pin actions, and add zizmor - #2310

Fix Python 3.8/3.9 jobs on Ubuntu 26.04, pin actions, and add zizmor#2310

EliahKagan merged 13 commits into

gitpython-developers:maingitpython-developers/GitPython:mainfrom

EliahKagan:claude/ci-ubuntu-26-old-pythons-and-action-pinsEliahKagan/GitPython:claude/ci-ubuntu-26-old-pythons-and-action-pinsCopy head branch name to clipboard