Deprecations in the github actions workflow

[finnagin]

It looks like main.yml is using a couple different things that have now been deprecated and currently fails if run on the develop branch. ubuntu-20.04 which deprecated in February and actions/upload-artifact@v3 which deprecated in the end of January.

Thoughts on bumping these to ubuntu-latest and actions/upload-artifact@v4?

Other options for the ubuntu runner could be ubuntu-22.04 and ubuntu-24.04, but I thought since macos-latest and windows-latest were used in the other parts of the workflow it might make sense to use ubuntu-latest as well so it doesn't need to be manually updated.