Support old pytorch versions that don't have weights_only.

comfy/utils.py

@@ -6,6 +6,10 @@ def load_torch_file(ckpt, safe_load=False):
         import safetensors.torch
         sd = safetensors.torch.load_file(ckpt, device="cpu")
     else:
+        if safe_load:
+            if not 'weights_only' in torch.load.__code__.co_varnames:
+                print("Warning torch.load doesn't support weights_only on this pytorch version, loading unsafely.")
+                safe_load = False
         if safe_load:
             pl_sd = torch.load(ckpt, map_location="cpu", weights_only=True)
         else: