* Fix: `ComplexWarning` Moved

Since NumPy 1.25+ and breaking in 2.0+, `ComplexWarning`
moved into its own sub-namespace for `exceptions`.

Ref.:
- https://numpy.org/doc/1.25/reference/generated/numpy.exceptions.ComplexWarning.html
- https://numpy.org/doc/stable/reference/generated/numpy.exceptions.ComplexWarning.html

* Support NumPy 2.0+