update test with example template

tests/async_engine/test_openapi_server_ray.py

@@ -1,10 +1,16 @@
+import os
+import pathlib
+
 import openai  # use the official client for correctness check
 import pytest
 
 from ..utils import RemoteOpenAIServer
 
 # any model with a chat template should work here
 MODEL_NAME = "facebook/opt-125m"
+chatml_jinja_path = pathlib.Path(os.path.dirname(os.path.abspath(
+    __file__))).parent.parent / "examples/template_chatml.jinja"
+assert chatml_jinja_path.exists()
 
 
 @pytest.fixture(scope="module")
@@ -16,7 +22,9 @@ def server():
         "--max-model-len",
         "2048",
         "--enforce-eager",
-        "--engine-use-ray"
+        "--engine-use-ray",
+        "--chat-template",
+        str(chatml_jinja_path),
     ]
 
     with RemoteOpenAIServer(MODEL_NAME, args) as remote_server: