Plan for CI Ubuntu 20 deprecations

It looks like GitHub actions are deprecating Ubuntu 20 which we use to build the binaries with the widest libc support 

https://github.blog/changelog/2025-01-15-github-actions-ubuntu-20-runner-image-brownout-dates-and-other-breaking-changes/

Do we just bump our min supported libc version? We don't have to worry about this until we need to create new releases after April 2025

