[upstream_ut] test_tensor_storage_type_xpu: storage_type() returns None on XPU

## Description
test_tensor_storage_type_xpu_* fail for all dtypes. Tensor.storage_type()
returns None on XPU instead of the expected typed storage class
(e.g. torch.FloatStorage, torch.BoolStorage, torch.ComplexDoubleStorage, ...).

## Error log
```
File "test/test_torch.py", line 302, in test_tensor_storage_type
self.assertEqual(a.storage_type(), expected_storage_type)
AssertionError: None mismatch: None is not
```

## Reproduce
```
python test/test_torch.py TestTorchDeviceTypeXPU.test_tensor_storage_type_xpu_float32
```

Run python test/test_torch.py TestTorchDeviceTypeXPU.test_tensor_storage_type_xpu_float32 and inspect test/test_torch.py around test_tensor_storage_type. Trace the XPU path used by Tensor.storage_type() for each dtype. Done means the XPU tests return the expected typed storage classes instead of None.

Written by the indexing model from the issue text.