Fix deprecation warnings from importlib and numpy

[bmorris3]

This PR fixes a few deprecation warnings:

1. Replaces the deprecated importlib.resources.path method with the new files() API

2. Drops the 1 in numpy.random.rand(1), and calls squeeze to resolve a similar issue where length-one vectors are being made where the result is expected to be scalar, since numpy 1.25:

DeprecationWarning: Conversion of an array with ndim > 0 to a scalar is deprecated, 
and will error in future. Ensure you extract a single element from your array 
before performing this operation. (Deprecated NumPy 1.25.)

Closes #360

[mfixstsci]

Changes look good! Thank you for the test as well @bmorris3 🤝