Replace virtualization detection with virt-what

[chuckleb]

This is a better system and can detect most/all virtualization platforms. This removes the clunky detect system with an automated one.

[chuckleb]

I will have to think about how to implement this as I was hoping to avoid downloading updates and rebuilding if the virtual OS image has everything in it. That's one of the advantages of a pre-built image, no need to run updates.

Currently, we do the OS detection before installing updates, but virt-what is simple shell script nor is it natively available, so would have to somehow bootstrap very early on.