[BUG] Creating an ndarray from ragged nested sequences is deprecated since numpy 1.24

[vcfgv]

Describe the bug
Numpy 1.24 deprecates ragged array creation will now always raise a ValueError unless dtype=object is passed. This includes very deeply nested sequences. Previously, VisibleDeprecationWarning: Creating an ndarray from ragged nested sequences (which is a list-or-tuple of lists-or-tuples-or ndarrays with different lengths or shapes) is deprecated. If you meant to do this, you must specify 'dtype=object' when creating the ndarray. will be thown.
Test case in test_multiclass.py, i.e. [np.array([]), np.array([1, 2, 3])], will raise AttributeError: 'list' object has no attribute 'array'

To Reproduce
To help us reproducing this bug, please provide information below:

1. Your Python version: v3.8.13
2. The version of Mars you use: master
3. Versions of crucial packages: numpy v1.24.1
4. Full stack of the error.
5. Minimized code to reproduce the error.

pytest mars/learn/utils/tests/test_multiclass.py::test_unique_labels_non_specific
or

import numpy as np
a = [np.array([]), np.array([1, 2, 3])]
np.asarray(a)

Expected behavior
ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.

Additional context
Add any other context about the problem here.