#gitlab release notes https://about.gitlab.com/releases/categories/releases/ full of duo on the left left and bring your own model on the right right, but no simple button, let alone a more elaborate solution, to require DCO on MRs I can find.
#github is full of copilot, too. but the DCO app is a button click away: https://github.com/apps/dco
how about #forgejo?