[XPU] check is_xccl_available before oneccl warmup (#39302)

Signed-off-by: Xinyu Chen <xinyu1.chen@intel.com>

vllm/v1/worker/xpu_worker.py

@@ -86,6 +86,7 @@ class XPUWorker(Worker):
         )
 
         # global all_reduce needed for overall oneccl warm up
+        if torch.distributed.is_xccl_available():
             torch.distributed.all_reduce(torch.zeros(1).xpu())
 
         # Set random seed.