Numpy >= 2.x appears to breaks things

[brews]

Dependabot's PR bumping numpy from v1.26.4 to v2.0.0 (#545) leads to failing tests in CI.

Specifically,

FAILED src/impactlab_tools/gcp/reindex.py::impactlab_tools.gcp.reindex.hierid_to_shapenum
FAILED src/impactlab_tools/gcp/reindex.py::impactlab_tools.gcp.reindex.shapenum_to_hierid

It would be great if we could get this to run smoothly across the numpy 2.0 divide.