ci(pre-commit): Check existing commit messages

Use new commitizen-branch hook to verify correctness of existing commit
messages post-commit and pre-push. This guards against cherry-picked
commits with invalid commit messages as well as empty commit messages
(e.g., created with git commit --allow-empty-message).

Author: Kurt-von-Laven

.pre-commit-config.yaml

@@ -17,6 +17,10 @@ repos:
     rev: v2.32.2 # automatically updated by Commitizen
     hooks:
       - id: commitizen
+      - id: commitizen-branch
+        stages:
+          - post-commit
+          - push
 
   - repo: local
     hooks: