remove lean4 from gradio block declaration, replace with python

app.py

@@ -183,7 +183,7 @@ def main():
                 submit = gr.Button("Send")
             with gr.Column():
                 json_out = gr.JSON(label="Full Output")
-                code_out = gr.Code(label="Extracted Lean4 Code", language="lean4")
+                code_out = gr.Code(label="Extracted Lean4 Code", language="python")
         state = gr.State([])
         # On submit, call chat_handler
         submit.click(chat_handler, [user_input, informal, max_tokens, state], [chat, json_out, code_out, state])