fix dtype

Author: jcaip

torchao/quantization/quantize_/workflows/int8/int8_tensor.py

@@ -60,6 +60,7 @@ class Int8Tensor(TorchAOBaseTensor):
     optional_tensor_attribute_names = [
         "block_size",
         "act_quant_kwargs",
+        "dtype",
     ]
 
     def __new__(
@@ -83,6 +84,7 @@ def __init__(
         scale: torch.Tensor,
         block_size: Optional[List[int]] = None,
         act_quant_kwargs: Optional[QuantizeTensorToInt8Kwargs] = None,
+        dtype: Optional[torch.dtype] = None,
     ):
         super().__init__()
         self.qdata = qdata