Make `asarray` behavior consistent with Python Array API. (#71757)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/70591
This PR makes `torch.asarray` consistent with [the Python Array API](https://data-apis.org/array-api/latest/API_specification/generated/signatures.creation_functions.asarray.html#signatures.creation_functions.asarray) (which also happens to be the same as `torch.as_tensor` behavior). Specifically, it makes `asarray` casting conditional to the presence of the `dtype` argument. This solves the issue when Python scalars (and lists) were passed as input without specifying the `dtype`.
Before:
```python
>>> torch.asarray([True, False])
tensor([1., 0.])
```
After:
```python
>>> torch.asarray([True, False])
tensor([True, False])
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71757
Reviewed By: mrshenli
Differential Revision: D33774995
Pulled By: anjali411
fbshipit-source-id: 9f293401f993dca4046ceb61f714773ed4cf7c46
(cherry picked from commit 0c6f98ebe7c843a68f624d2d9c3cae39f018bb66)
