KN-PMP: solve standard PMP once any k>=p

[jGaboardi]

Currently within the $k$-nearest $p$-median problem, we raise errors here¹ and here² when any values of k is greater than p. Perhaps we should keep this behavior in from_geodataframe(), but in _create_sparse_matrix() we should probably consider throwing a warning then defaulting to solve a standard $p$-median problem.

This should be considered after v0.6.0 – #414

xref #425

Footnotes

1. in _create_sparse_matrix() ↩

2. in from_geodataframe() ↩