remove commented out code

Signed-off-by: Jeffrey Martin <[email protected]>

garak/attempt.py

@@ -174,7 +174,6 @@ def __setattr__(self, name: str, value: Any) -> None:
         if name == "prompt":
             if value is None:
                 raise TypeError("'None' prompts are not valid")
-            # assert isinstance(value, str)
             self._add_first_turn("user", value)
 
         elif name == "outputs":