[DismissableLayer] Fix race condition between layers closing at the same time

[trevorharwell]

Description

I encountered a bug where multiple layers closing at the same time would both determine that context.layersWithOutsidePointerEventsDisabled.size > 1 which prevented the pointer events from being reset back to it's original value. By moving the context.layersWithOutsidePointerEventsDisabled.delete(node) to inside of the clean up method for the outer events hook, the race condition is resolved.

I see the comment about "We purposefully prevent combining this effect with the disableOutsidePointerEvents effect" which this PR might not be aligned with. My thought is that the context.layers could represent the "creation order" while context.layersWithOutsidePointerEventsDisabled would not need to adhere to that.