COMPAT: fix numpy 2.0 incompatibility

[martinfleis]

Closes #722

The issue probably won't pop-up for users given it is in the legacy implementation you would need to import directly.

Also adding numpy nightly to dev env.

[martinfleis]

The CI still did not pick up numpy 2 in dev env... I am afraid I'd need to manually install it in another step as it gets pulled by plenty of other deps before we get to the pip part. I will revert that and keep just that fix.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.9%. Comparing base (e82d1be) to head (0a9a58f).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main    #723   +/-   ##
=====================================
  Coverage   83.9%   83.9%           
=====================================
  Files        145     145           
  Lines      15583   15583           
=====================================
  Hits       13077   13077           
  Misses      2506    2506           

Files	Coverage Δ
libpysal/cg/voronoi.py	73.7% <100.0%> (ø)
libpysal/examples/remotes.py	76.4% <100.0%> (ø)

[jGaboardi]

Are we going to fix the failure in the PR or in a subsequent PR?

[martinfleis]

Are we going to fix the failure in the PR or in a subsequent PR?

I'd say so. I don't know why we see it, so it will require more time to figure out.