[fix] don't expose unique_dim in torch (#63080)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/62793
This is mostly a quick fix. I think the more correct fix could be updating `unique_dim` to `_unique_dim` which could be BC-breaking for C++ users (� maybe). Maybe something else I am missing.
~~Not sure how to add a test for it.~~ Have tested it locally.
We can add a test like following. Tested this locally, it fails currently but passes with the fix.
```python
def test_wildcard_import(self):
exec('from torch import *')
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/63080
Reviewed By: gchanan
Differential Revision: D30738711
Pulled By: zou3519
fbshipit-source-id: b86d0190e45ba0b49fd2cffdcfd2e3a75cc2a35e
