Gitlab is very complex and a heavy resource hog. You probably don't need it. Most small to medium enterprises can comfortably host their projects on lightweight forgejo or gitea (speaking from experience). They even have functionality similar to github actions. If you need anything more complex, you are better off integrating another self hosted external service to the mix.

https://forgejo.org/ here's a little better example, though you did a great job doing some proposal, gotta love those who do at least some initiative