If possible, get rid of any x86 specific parts of the XVM release build

[lagergren]

Ideally we would like to get rid of the EnVar plugin, as there is no official way to install it, and becasue it is x86 code only.There is probably a better way to get environment variables into an "nsi" installation file for Windows, and it would be worth a lot if we could generate the Windows installer on any platform. The nsis tools happily run on all known silicons, but EnVar does not.

We currently provide a container configuration that can cross-compile the releases for us on any platform, including on Apple silicon through Docker buildit emulation. This in the "xdk-release" repository under the xtclang org.