Convert examples to ruff-format (#18400)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

examples/online_serving/utils.py

@@ -16,10 +16,10 @@ def get_first_model(client: OpenAI) -> str:
             f"{client.base_url} with API key {client.api_key}. Check\n"
             "1. the server is running\n"
             "2. the server URL is correct\n"
-            "3. the API key is correct") from e
+            "3. the API key is correct"
+        ) from e
 
     if len(models.data) == 0:
-        raise RuntimeError(
-            f"No models found on the vLLM server at {client.base_url}")
+        raise RuntimeError(f"No models found on the vLLM server at {client.base_url}")
 
     return models.data[0].id