XTaskQueueSetCurrentProcessTaskQueue SAL should use _In_opt_.

The SAL for XTaskQueueSetCurrentProcessTaskQueue is incorrect; it should be allowing a null parameter.

/// <summary>
/// Sets the given task queue as the process wide task queue.  The
/// queue can be set to nullptr, in which case XTaskQueueGetCurrentProcessTaskQueue will
/// also return nullptr. The provided queue will have its handle duplicated
/// and any existing process task queue will have its handle closed.
/// </summary>
/// <param name='queue'>The queue to set up as the default task queue for the procces.</param>
STDAPI_(void) XTaskQueueSetCurrentProcessTaskQueue(
    _In_ XTaskQueueHandle queue
    ) noexcept;

That should use _In_opt_.

Start from the XTaskQueueSetCurrentProcessTaskQueue declaration shown in the issue and inspect the surrounding public API declarations. Update the queue parameter annotation to allow nullptr, then verify that the declaration matches the documented behavior and any related API checks.