[Fix] Remove deprecated o1-preview from O-series test and deduplicate is_o_series check

o1-preview is deprecated and not in the model registry with supports_reasoning=True,
causing the Azure O-series config test to fail. Also removed a duplicate is_o_series
assignment in utils.py.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

litellm/utils.py

@@ -8397,11 +8397,6 @@ class ProviderConfigManager:
                 or (supports_reasoning(model) and not is_gpt_model)
             )
 
-            is_o_series = model and (
-                "o_series" in model.lower()
-                or (supports_reasoning(model) and not is_gpt_model)
-            )
-
             if is_o_series:
                 return litellm.AzureOpenAIOSeriesResponsesAPIConfig()
             else:

tests/test_gpt5_azure_temperature_support.py

@@ -24,7 +24,7 @@ def test_azure_gpt5_supports_temperature():
 
 def test_azure_o_series_does_not_support_temperature():
     """Test that Azure O-series models still use the correct O-series config."""
-    test_models = ["o1", "o1-preview", "o3"]
+    test_models = ["o1", "o3"]
     
     for model in test_models:
         config = ProviderConfigManager.get_provider_responses_api_config(