Promoting the Actor implmentation from edge to proper concurrent-ruby?

We've been using the Actor implementation from the edge in https://github.com/Dynflow/dynflow for a while and we've hit no issues. Seems like it might be ready to get promoted to the concurrent-ruby proper.

It would also help us with some obstacles we have right now when delivering our code on debian (see https://github.com/theforeman/foreman-packaging/pull/3438).

Start by reviewing the Actor implementation on the edge branch and how Dynflow uses it. Check the linked Foreman packaging pull request for the Debian obstacle and compare the requirements for promotion into concurrent-ruby proper. Done means the promotion scope and release or packaging changes are agreed.