In addition to the other commenters, the actual license can be found at https://gitlab.com/gitlab-org/gitlab-ee/blob/master/LICENSE

"This software and associated documentation files (the "Software") may only be used if you (and any entity that you represent) have agreed to, and are in compliance with, the GitLab Subscription Terms of Service, available at https://about.gitlab.com/terms/#subscription (the “EE Terms”), and otherwise have a valid GitLab Enterprise Edition subscription for the correct number of user seats."