Install xz as regular dependency

[kattouf]

I found a corner case when previous xz install on macOS implementation doesn't work and propose a solution.

The previous implementation covered cases when we installed ruby-install on macOS via brew and that worked well.
But in our case, we install (implicitly) ruby-install using mise, that don't use brew to install it under the hood, and as a consequence we miss brew formula dependencies installation.

I propose to install xz as part of installing all other dependencies (via system package managers) that cover all cases.