Ive never used githubs CI/CD, but gitlab has quite a large ecosystem for its CI/CD.
Seems to me like you could use gitlab as a one-stop-shop to host everything from your code to your artifacts and containers, if you are willing to pay for those fancy features
Free is able to just do basic CI/CD for like 250 minutes a month, or unlimited via your own runners/build servers, thats about it
Because paying a few grand a year for a certificate somehow makes your software more trustworthy