Note: This will not work and cannot work on repos that use signed commits from multiple authors.
Signed git history is immutable, and unsigned git history is a supply chain attack vector.
That said I could see this being useful for single-author WIP branches doing cleanup before a PR
added a warning for this in v0.2.0 signed commits now flag before the rewrite, it can know resign rebuilt commits with your key.
https://github.com/TheRealYT/git-knife/releases/tag/v0.2.0