Bugfix/np bool deprecation

[jack-mcivor]

np.bool was deprecated in NumPy 1.20.0. Reference:

• https://numpy.org/doc/stable/release/1.20.0-notes.html#using-the-aliases-of-builtin-types-like-np-int-is-deprecated
• https://numpy.org/doc/stable/user/basics.types.html#array-types-and-conversions-between-types

This call became an error in NumPy 1.24.0, see https://numpy.org/doc/stable/release/1.24.0-notes.html#expired-deprecations

[jack-mcivor]

@ryan-wolbeck done