fix(chatgpt): omit temperature from subscription requests (#6498)

Co-authored-by: Raul <9117159+raultcj@users.noreply.github.com>

src/llm_core.py

@@ -1556,8 +1556,9 @@ def _build_chatgpt_responses_payload(
         "stream": stream,
         "store": False,
     }
-    if not _restricts_temperature(model):
-        payload["temperature"] = temperature
+    # ChatGPT plan Responses requests reject temperature for every model.
+    # The common caller still passes its preset value, but this provider must
+    # omit the field even for model names outside the known reasoning families.
     # ChatGPT Subscription Codex API does not support max_output_tokens —
     # passing it returns HTTP 400 "Unsupported parameter: max_output_tokens".
     # Do not include it in the payload.