fix: update last_code_generated in smart_dataframe's __init__.py (#1484)

In SmartDataframe class the last_code_generated property returned _agent.last_code_executed instead of _agent.last_code_generated. In SmartDatalake it is implemented properly.

Co-authored-by: Bence Kecskés <[email protected]>

pandasai/smart_dataframe/__init__.py

@@ -171,7 +171,7 @@ def last_prompt_id(self) -> uuid.UUID:
 
     @property
     def last_code_generated(self):
-        return self._agent.last_code_executed
+        return self._agent.last_code_generated
 
     @property
     def last_code_executed(self):