We use a self hosted gitlab-ce instance which has pretty high up time running on a 10 year old server (and its backup)

Takes a few minutes a month to update and babysit. We only basically use the CI and the repository functionality though so gitlab has been "feature complete" for us for a while. Probably I we could swap to something like gitea or forgeo but the gitlab CI seems like a nice balance between powerful when it needs to be and simple otherwise for our use case so there is nothing driving us to swap.