Fix broken test_affine_quantized_tensor_parallel test after DeviceMesh (#3151)

fix broken test_affine_quantized_tensor_parallel test after DeviceMesh update

Author: danielvegamyhre

test/dtypes/test_affine_quantized_tensor_parallel.py

@@ -115,7 +115,7 @@ def forward(self, x: torch.Tensor) -> torch.Tensor:
         dn_quant(up_quant(example_input))
 
         mesh = self.build_device_mesh()
-        mesh.device_type = "cuda"
+        mesh._device_type = "cuda"
 
         # Shard the models
         up_dist = self.colwise_shard(up_quant, mesh)