Move Che Theia nightly/main builds from ci.centos.org to GitHub Actions

[azatsarynnyy]

Is your task related to a problem? Please describe.

As Red Hat supported ci.centos.org is going to be deprecated soon, we need to migrate Che Theia nightly/main builds to more community-friendly GitHub Actions.

Describe the solution you'd like

Implement Che Theia nightly/main builds as GitHub Workflow.

Describe alternatives you've considered

Additional context

https://github.com/eclipse/che-theia/blob/master/cico_build_master.sh

[benoitf]

here the most difficult part is to grab the keys to deploy on Akamai/cdn