CI adjustment needed for numpy>=2.1.0.dev0

[jGaboardi]

• We are seeing 14 failures in DEV CI due upstream numpy>=2.1.0.dev0.
• All are docstring Examples failures, so maybe we simply cast as vanilla floats there?

[sjsrey]

Thanks for flagging this.

I think we should deprecate the _indices.py module as much of this is now in segregation anyway and we have always had this as a private module in inequality.

Moving this out of inequality would allow for a clearer separation between segregation and inequality as well.