Don't try to get vram from xpu or cuda when directml is enabled.

comfy/model_management.py

@@ -34,6 +34,9 @@ if args.directml is not None:
 
 try:
     import torch
+    if directml_enabled:
+        total_vram = 4097 #TODO
+    else:
         try:
             import intel_extension_for_pytorch as ipex
             if torch.xpu.is_available():