Fix Gradio compatibility - update to latest version

app.py

@@ -233,7 +233,7 @@ with gr.Blocks(title="PromptPrepML", theme=gr.themes.Soft()) as demo:
                 value="Prepare this dataset for machine learning. Handle missing values, remove identifier columns, extract date features, encode categorical variables, and scale numeric features.",
                 lines=3
             )
-            process_btn = gr.Button("🚀 Process Dataset", variant="primary", size="lg")
+            process_btn = gr.Button("🚀 Process Dataset", variant="primary")
         
         with gr.Column(scale=2):
             output_summary = gr.Markdown(label="📊 Results Summary")