[UR][L0v2] remove cross-queue async allocations (#21320)
Queue asynchronous allocations are currently capable of taking memory
deallocated from other queues. This adds implicit synchronization,
and might lead to non-obvious performance impact on applications.
On top of that, the current implementation of this functionality
requires all deallocations to always create signal events,
potentially impacting performance in the hot path.
This patch simplifies this logic, only creating signal events when
truly required (for out-of-order queues). The downside is that
cross-queue async allocations will no longer happen implicitly.
