[Build] Fix the name of the threading package setting.
[Build] Fix the name of the threading package setting.

I'd renamed the setting, but failed to update build-presets.ini.

rdar://90776105

apple/swift,benlangmuir/swift,benlangmuir/swift,roambotics/swift,benlangmuir/swift,roambotics/swift,JGiola/swift,JGiola/swift,JGiola/swift,roambotics/swift,roambotics/swift,apple/swift,glessard/swift,apple/swift,glessard/swift,roambotics/swift,benlangmuir/swift,JGiola/swift,apple/swift,apple/swift,benlangmuir/swift,JGiola/swift,roambotics/swift,JGiola/swift,apple/swift,glessard/swift,benlangmuir/swift,glessard/swift,glessard/swift,glessard/swift