openai[patch]: enable streaming for o1 (#29823)

Verified streaming works for the `o1-2024-12-17` snapshot as well.

libs/partners/openai/langchain_openai/chat_models/base.py

@@ -511,15 +511,6 @@ class BaseChatOpenAI(BaseChatModel):
             values["temperature"] = 1
         return values
 
-    @model_validator(mode="before")
-    @classmethod
-    def validate_disable_streaming(cls, values: Dict[str, Any]) -> Any:
-        """Disable streaming if n > 1."""
-        model = values.get("model_name") or values.get("model") or ""
-        if model == "o1" and values.get("disable_streaming") is None:
-            values["disable_streaming"] = True
-        return values
-
     @model_validator(mode="after")
     def validate_environment(self) -> Self:
         """Validate that api key and python package exists in environment."""