Earlier quoted context omitted.
Just host your own runners https://docs.gitlab.com/runner/install/
That requires on-prem hardware (or I guess you could spin VMs up in the cloud, but I doubt that works out cheaper than hosted CI).
Depending on your needs, automatically managing and deploying this could also be interesting. We have started a new project called the "5 min production app": https://about.gitlab.com/blog/2020/12/15/first-code-to-ci-cd...
Alternatively, partners provide hosted runners, if that is an option for you: https://partners.gitlab.com/English/directory/search?f0=Serv...