Avoid creating helper functions in options

pysr/sr.py

@@ -1581,6 +1581,8 @@ class PySRRegressor(MultiOutputMixin, RegressorMixin, BaseEstimator):
             early_stop_condition=early_stop_condition,
             seed=seed,
             deterministic=self.deterministic,
+            extend_user_operators=False,
+            define_helper_functions=False,
         )
 
         # Convert data to desired precision