Cleaning it would change the commit ID, so a forge cannot clean it even if it wanted to (not without rewriting all descendant commits too and breaking signed co

Cleaning it would change the commit ID, so a forge cannot clean it even if it wanted to (not without rewriting all descendant commits too and breaking signed commits, at least). The change-id is exactly as much part of the commit object as the author/committer name/timestamp, description, parent commit ID, tree, and participates in the commit hashing as those do.