Mac profiler compilation error (jthread, stop_token) (+ temp fix)

[Mala9898]

Clang does not suport jthread
include/ppqsort/parallel/cpp/mainloop_par.h:138:58: error: no member named 'jthread' in namespace 'std'; did you mean 'thread'? 138 | int threads = static_cast<int>(std::jthread::hardware_concurrency())) { | ~~~~~^~~~~~~ | thread

this introduces the problem
1c1faef

a fix is waiting to be merged
GabTux/PPQSort#1

But in meantime the easiest workaround is to use this commit
git checkout 684c34dc21e123b608e962d026d8c40ff0abe5ee

Hopefully this saves any reader from wasting an entire morning on messing with toolchains

[foxtran]

My patch is really stupid. It does not support a proper cancellation if main thread of program was stopped.