provide a default value for compile so @build runs (#912)

06_gpu_and_ml/stable_diffusion/flux.py

@@ -120,7 +120,7 @@
 )
 class Model:
     compile: int = (  # see section on torch.compile below for details
-        modal.parameter()
+        modal.parameter(default=0)
     )
 
     def setup_model(self):