@Gina Ooft - tough one! Every govt agency I've worked for has a lot of experience with their own, already self hosted GitLab instances. The GitLab runner configurations, and GitLab components (pipelines) are marvellous. Enterprise edition has great integration with SSO, allow you to configure rights and permissions based on group membership. Besides that I think there's the matter of support.
But, speaking from ideology and license perspective; Forgejo without a doubt.