[Concurrency][Windows] Remove unnecessary includes.
[Concurrency][Windows] Remove unnecessary includes.

TaskLocal.cpp doesn't need <handleapi.h> or <processthreadsapi.h>, both of
which want <windows.h>, which isn't included any more.

rdar://90776105

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