unimol_tools do not make use of gpu when infer

The code implemented in unimol_tools did not pass the `cuda` variable to `Trainer`, so the gpu won't be used.

The related code is [here](https://github.com/dptech-corp/Uni-Mol/blob/c458c0fae2318b6bf49fed51f56fdc8d4b7003e1/unimol_tools/unimol_tools/predictor.py#L90).

Should be changed like this:
```python
self.trainer = Trainer(task='repr', cuda=self.device)
```