Support for running on Apple Silicon (arm64)

[LinusU]

Currently, the binary shipped in app-builder-bin is only built for x86_64, would it be possible to have it be a universal binary with support for arm64 as well?

$ file node_modules/app-builder-bin/mac/app-builder
node_modules/app-builder-bin/mac/app-builder: Mach-O 64-bit executable x86_64

[LinusU]

It seems like go build cannot produce universal binaries on its own. ref: https://github.com/golang/go/issues/40698

On macOS this isn't a problem since we have lipo, but if we are cross compiling from e.g. Linux to macOS than it becomes a bit more tricky... One option is to ship two binaries instead, and have the js script pick the appropriate one...