Amd test fp8 (#4261)

python/sglang/srt/layers/quantization/fp8_utils.py

@@ -32,6 +32,10 @@ if _is_cuda:
     else:
         from sgl_kernel import fp8_scaled_mm
 
+# Input scaling factors are no longer optional in _scaled_mm starting
+# from pytorch 2.5. Allocating a dummy tensor to pass as input_scale
+TORCH_DEVICE_IDENTITY = torch.ones(1, dtype=torch.float32)
+
 
 def cutlass_fp8_supported():
     if not _is_cuda: