Github PRs do not make it easy for you to sign merge commits. It's possible in gitlab to my knowledge but in github it's a pain in the ass. And github needlessl

Github PRs do not make it easy for you to sign merge commits. It's possible in gitlab to my knowledge but in github it's a pain in the ass. And github needlessly touches PR commits so that even if you could fast-forward merge/rebase the PR while keeping signatures in tact, github will still regenerate your commits, breaking the hashes and signatures.