test_nonzero in test_searching_functions.py incorrectly handle 0d inputs

[oleksandr-pavlyk]

xp.nonzero is documented in the spec to require an exception for 0d arrays:

x (array) – input array. Must have a positive rank. If x is zero-dimensional, the function must raise an exception.

Yet the code exercises xp.nonzero for zero-dimensional arrays and expects the function to returns a tuple of size 1:

array-api-tests/array_api_tests/test_searching_functions.py

Lines 93 to 98 in f82c7bc

	out = xp.nonzero(x)
	if x.ndim == 0:
	assert len(out) == 1, f"{len(out)=}, but should be 1 for 0-dimensional arrays"
	else:
	assert len(out) == x.ndim, f"{len(out)=}, but should be {x.ndim=}"
	out_size = math.prod(out[0].shape)

This discrepancy should be fixed, or the spec modified.