[UR] Mark urUSMHostMemRegisterTest as known failure on L0v2 (#21655)
The urUSMHostMemRegisterTest.Success test intermittently fails on
Level-Zero V2 with UR_RESULT_ERROR_OUT_OF_DEVICE_MEMORY during
urEnqueueUSMMemcpy after registering host memory.
Add uur::LevelZeroV2{} to the UUR_KNOWN_FAILURE_ON list to disable
this test on L0v2 until the root cause is resolved.
Ref: intel/llvm#21633
Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>