Fix Scalar(bool) handling in toIValue (#87179)
At the moment, they were casted to `int64`, which breaks quite a few
casting rules for example in `ops.aten`.
Quite a vintage bug, circa 2020.
With this fix, the following code prints `torch.bool`, rather than `torch.int64`.
```python
import torch
msk = torch.tensor([False])
b = torch.tensor([False])
print(torch.ops.aten.where.ScalarSelf(msk, True, b).dtype)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/87179
Approved by: https://github.com/albanD
