Fix RUF001 lint issue

mesa/agent.py

@@ -56,7 +56,7 @@ def __init__(self, unique_id: int, model: Model) -> None:
             self.model.agentset_experimental_warning_given = False
 
             warnings.warn(
-                "The Mesa Model class wasn’t initialized. In the future, you need to explicitly initialize the Model by calling super().__init__() on initialization.",
+                "The Mesa Model class wasn't initialized. In the future, you need to explicitly initialize the Model by calling super().__init__() on initialization.",
                 FutureWarning,
                 stacklevel=2,
             )