chore: fetch origin

dev/flake.nix

@@ -43,15 +43,17 @@
             meta.description = "Verify commit messages from the default branch to HEAD follow conventional commit format";
             text = ''
               default_branch=$(git remote show origin | grep 'HEAD branch' | cut -d' ' -f5)
-              current_commit=$(git rev-parse HEAD)
 
-              commit_count=$(git rev-list --count "$default_branch".."$current_commit")
+              # github actions does a shallow copy, which will fail when queried on `$default_branch..HEAD`
+              git fetch origin "$default_branch"
+
+              commit_count=$(git rev-list --count "$default_branch"..HEAD)
 
               if [ "$commit_count" -eq 0 ]; then
                   echo "No commits to check between $default_branch and HEAD."
               else
                   echo "Checking $commit_count commit(s)..."
-                  cz check --rev-range "$default_branch".."$current_commit"
+                  cz check --rev-range "$default_branch"..HEAD
               fi
             '';
           };