@bortzmeyer @eu_os I was in a similar situation for a professional project and compared both Forgejo and Gitlab (CE, Community Edition). What I found was that important, IMHO basic, features are paywalled by Gitlab and need a per user subscription (see https://about.gitlab.com/pricing/feature-comparison/ ). Also, participating in upstream development is a lot more open at Forgejo, IMHO.
See also the article on why Fedora decided to switch to Forgejo: https://fedoramagazine.org/fedora-moves-towards-forgejo-a-unified-decision/