Revert "Enable streaming on o1 since it's now supported"

This was done too soon, as non-preview o1 doesn't support streaming at the moment

This reverts commit 3badc07.

Author: codeofdusk

src/gptcmd/llm/openai.py

@@ -157,6 +157,9 @@ def _estimate_cost_in_cents(
             + Decimal(sampled_tokens) * sampled_scale
         ) * Decimal("100")
 
+    def _supports_streaming(self) -> bool:
+        return not self.model.startswith("o1")
+
     def complete(self, messages: Sequence[Message]) -> LLMResponse:
         kwargs = {
             "model": self.model,
@@ -228,11 +231,16 @@ def validate_api_params(self, params):
 
     @property
     def stream(self) -> bool:
-        return self._stream
+        return self._supports_streaming() and self._stream
 
     @stream.setter
     def stream(self, val: bool):
-        self._stream = val
+        if not self._supports_streaming():
+            raise NotImplementedError(
+                "Streamed responses are not supported by this model"
+            )
+        else:
+            self._stream = val
 
     @property
     def valid_models(self) -> Iterable[str]: