fix: replace deprecated gr.update() with gr.Dropdown() for Gradio 5.x

app.py

@@ -318,8 +318,8 @@ def run_demo(processor, num_cores, neurons_per_core, neuron_model,
 
 def get_neuron_models(processor):
     """Return available neuron models for selected processor."""
-    return gr.update(choices=PROCESSORS[processor]["neuron_models"],
-                     value=PROCESSORS[processor]["neuron_models"][0])
+    models = PROCESSORS[processor]["neuron_models"]
+    return gr.Dropdown(choices=models, value=models[0])
 
 
 def get_processor_info(processor):