[BUGFIX] utils.py - bool = bool

[mwunderl]

Description

Importing mxnet with numpy 1.20+ results in

AttributeError: module 'numpy' has no attribute 'bool'.
np.bool was a deprecated alias for the builtin bool. To avoid this error in existing code, use bool by itself. Doing this will not modify any behavior and is safe. If you specifically wanted the numpy scalar type, use np.bool_ here. The aliases was originally deprecated in NumPy 1.20; for more details and guidance see the original release note at:
https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations

np.bool was a deprecated alias for the builtin bool, so replace np.bool with bool

Tested locally with mxnet-1.9.1-py3-none-manylinux2014_x86_64.whl , numpy 1.24.4, python 3.10.12

Checklist

Essentials

• [ x] PR's title starts with a category (e.g. [BUGFIX], [MODEL], [TUTORIAL], [FEATURE], [DOC], etc)
• [x ] Changes are complete (i.e. I finished coding on this PR)
• [x ] All changes have test coverage
• [ x] Code is well-documented

cf #21165

[mxnet-bot]

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