Use GetActiveProcessorCount and the ALL_PROCESSOR_GROUPS const provided
in golang.org/x/sys/windows. The function is available on Windows 7 and
later. Go requires Windows 7, see https://go.dev/doc/go1.11#ports
ret,_,_:=procGetActiveProcessorCount.Call(uintptr(0xffff))// ALL_PROCESSOR_GROUPS is 0xffff according to Rust's winapi lib https://docs.rs/winapi/*/x86_64-pc-windows-msvc/src/winapi/shared/ntdef.rs.html#120