Refactor app.py to include citation button with markdown

app.py

@@ -173,12 +173,7 @@ with demo:
 
     with gr.Row():
         with gr.Accordion("📙 Citation", open=False):
-            citation_button = gr.Textbox(
-                value=gr.Markdown("```bib\n" + CITATION_BUTTON_TEXT + "\n```"),
-                label=CITATION_BUTTON_LABEL,
-                elem_id="citation-button",
-                show_copy_button=True,
-            )
+            gr.Markdown("```bib\n" + CITATION_BUTTON_TEXT + "\n```")
 
 scheduler = BackgroundScheduler()
 scheduler.add_job(restart_space, "interval", seconds=1800)