Rip out all the code that implements VirtualMachine processing

[prioux]

This is all, at this point, crud in the codebase. It's never used and the use cases have disappeared with modern clusters and containerization.

Hints to find the code:

exception class: NoVmAvailableError 
file: scir_cloud.rb
file: scir_amazon.rb

[MontrealSergiy]

somehow, time by time, I hear of potential commercial partners interested in a demo with amazon VMs, though, for some reason, Magic Castle is typically used

[prioux]

This issue has nothing to do with setting VMs as Bourreaux. It's about the subsystem that launches VMs as task handlers.