Codeberg is a community driven project, which provides CI for FOSS projects, and it's a bit unfair to expect them to provide free compute for random and/or private projects.
For what it's worth, I've had better experience with running self-hosted Forgejo Actions runners compared to self-hosted Github Actions runners.
I have several projects I’d want to move over but thats enough of a barrier for me to lose interest. There’s also Forgejo Actions but I assume paying for your own runner is probably more expensive than GitHub.
Codeberg has free Forgejo Actions instance that you can use without a request, but with limited resources[1]:
> own runner is probably more expensive than GitHub
You can rent a VPS for as cheap as $15/year or run it locally.
However I would not trust external contributors' code on my server.