We've been using gitea since 2019 with no problems. Drone for CI, although these days you can just stick with the built-in "actions". It's always funny reading the news about yet another GitHub outage, when our gitea instance hasn't had a minute of unplanned downtime in 6 years. (And very little of planned downtime, always in non-working hours.)

Whatever the current gitea is named this year. See codeberg.org. I think currently it is called Forgejo

https://forgejo.org/compare-to-gitea/

We use gitlab at my company. the k8s yaml files are a bit complicated but the simpler shell based ones (publishing npm packages, etc.) are pretty straight forward