Method request_stop

include/exec/timed_thread_scheduler.hpp:241–246

    }

    void request_stop()
    {
      std::scoped_lock lock{ready_mutex_};
      stop_requested_ = true;
      cv_.notify_one();
    }

    STDEXEC::__intrusive_mpsc_queue<&command_type::next_> command_queue_;
    intrusive_heap<task_type,