[ci][distributed] disable hanging tests (#10317)

Signed-off-by: youkaichao <youkaichao@gmail.com>

tests/distributed/test_utils.py

@@ -117,6 +117,7 @@ def allgather_worker(rank, WORLD_SIZE, port1, port2):
     pg1.barrier()
 
 
+@pytest.mark.skip(reason="This test is flaky and prone to hang.")
 @multi_gpu_test(num_gpus=4)
 @pytest.mark.parametrize(
     "worker", [cpu_worker, gpu_worker, broadcast_worker, allgather_worker])