empty_like does not respect the shape argument if it is ()

The [`empty_like` function](https://numpy.org/devdocs/reference/generated/numpy.empty_like.html) recently learnt a `shape` argument in gh-13046.

However, this argument is not always respected:
```python
>>> a = np.zeros(2)
>>> np.empty_like(a, shape=4).shape
(4,)
>>> np.empty_like(a, shape=()).shape
(2,)  # bug
```