Proposed new feature or change:

The Array API standard says that np.nonzero should throw an exception for 0D input.

Currently, np.nonzero implicitly makes 0D input a 1D (with atleast_1d), no warning is raised a warning is raised. In its docstring it says:

       .. deprecated:: 1.17.0

          Use `atleast_1d` explicitly if this behavior is deliberate.

Also np.array(1).nonzero() gives a deprecation warning:

DeprecationWarning: Calling nonzero on 0d arrays is deprecated, as it behaves surprisingly. Use `atleast_1d(arr).nonzero()` if the old behavior was intended.

Do we want to throw an exception on 0D input for both cases for Array API compatibility?