Knope generates duplicate changelog entries when a merge commit and the commit it merges in have the same conventional commit title

[mdaniels5757]

E.g. NixOS/nixpkgs-vet#248. (PR titles are used in merge commit messages automatically on GitHub when configured to do so in the repository settings, and we have it so configured.)

I'm not quite sure what I think Knope should do, though. It could filter out when the subjects are literally identical (except for the (#xxx) at the end), and that would take care of the common case for me. But it would also be nice to have a Knope option to ignore merge commits entirely for conventional-commit purposes.