Config: Removes Threads option

This is an option that has been long overdue for removal. It's original
intention was primarily to lie to the guest application about the number
of cores in the system. This allowed us to say that the system was only
single threaded which worked around some threading bugs that we had
early on.

This is no longer the case and now it is a confusing remnant of the past
that people think they need to set. Incorrectly assuming that "0" by
default means that FEX is doing some sort of disabling of threading and
forcing all emulation down one CPU core. This is not the case and has
never been the case, so removing the option makes that idea go away.

FEXCore/Source/Interface/Config/Config.cpp

@@ -321,16 +321,6 @@ namespace DefaultValues {
     Meta->Load();
 
     // Do configuration option fix ups after everything is reloaded
-    {
-      // Always fix up the number of threads and create the configuration
-      // Otherwise the application could receive zero as the number of threads
-      FEX_CONFIG_OPT(Cores, THREADS);
-      if (Cores == 0) {
-        // When the number of emulated CPU cores is zero then auto detect
-        FEXCore::Config::EraseSet(FEXCore::Config::CONFIG_THREADS, fextl::fmt::format("{}", FEXCore::CPUInfo::CalculateNumberOfCPUs()));
-      }
-    }
-
     if (FEXCore::Config::Exists(FEXCore::Config::CONFIG_CORE)) {
       // Sanitize Core option
       FEX_CONFIG_OPT(Core, CORE);