Fix flaky hicache test with mooncake backend (#11953)

Signed-off-by: Shangming Cai <csmthu@gmail.com>

test/srt/hicache/test_hicache_storage_mooncake_backend.py

@@ -201,9 +201,9 @@ class HiCacheStorageMooncakeBackendBaseMixin(HiCacheStorageBaseMixin):
         # Set the environment variables for Mooncake using dynamic ports
         env_vars = {
             "MOONCAKE_MASTER": f"127.0.0.1:{cls.mooncake_master_port}",
-            "MOONCAKE_PROTOCOL": "rdma",
+            "MOONCAKE_PROTOCOL": "tcp",
             "MC_MS_AUTO_DISC": "0",
-            "MOONCAKE_DEVICE": get_rdma_devices_args(),
+            "MOONCAKE_DEVICE": "",
             "MOONCAKE_TE_META_DATA_SERVER": f"http://127.0.0.1:{cls.mooncake_metadata_port}/metadata",
             "MOONCAKE_GLOBAL_SEGMENT_SIZE": "4294967296",  # 4 GiB
         }