enh: reasoning_effort param support for openai

backend/open_webui/utils/payload.py

@@ -47,6 +47,7 @@ def apply_model_params_to_body_openai(params: dict, form_data: dict) -> dict:
         "top_p": float,
         "max_tokens": int,
         "frequency_penalty": float,
+        "reasoning_effort": str,
         "seed": lambda x: x,
         "stop": lambda x: [bytes(s, "utf-8").decode("unicode_escape") for s in x],
     }