DOC: correct Voronoi docstring (#13735)
DOC: correct Voronoi docstring (#13735)

* the `Voronoi` class docstring refers to the construction
of the incorrect type of geometric diagram--likely a copy-paste
error from the `ConvexHull` docstring above
rgommers/scipy,WarrenWeckesser/scipy,ilayn/scipy,zerothi/scipy,Eric89GXL/scipy,WarrenWeckesser/scipy,vigna/scipy,andyfaff/scipy,rgommers/scipy,ilayn/scipy,Stefan-Endres/scipy,endolith/scipy,zerothi/scipy,tylerjereddy/scipy,mdhaber/scipy,ilayn/scipy,perimosocordiae/scipy,andyfaff/scipy,e-q/scipy,endolith/scipy,tylerjereddy/scipy,Eric89GXL/scipy,e-q/scipy,Eric89GXL/scipy,WarrenWeckesser/scipy,Eric89GXL/scipy,tylerjereddy/scipy,andyfaff/scipy,endolith/scipy,anntzer/scipy,Eric89GXL/scipy,tylerjereddy/scipy,e-q/scipy,grlee77/scipy,rgommers/scipy,e-q/scipy,zerothi/scipy,andyfaff/scipy,Stefan-Endres/scipy,grlee77/scipy,grlee77/scipy,grlee77/scipy,vigna/scipy,scipy/scipy,matthew-brett/scipy,matthew-brett/scipy,scipy/scipy,zerothi/scipy,rgommers/scipy,matthew-brett/scipy,mdhaber/scipy,scipy/scipy,ilayn/scipy,anntzer/scipy,vigna/scipy,endolith/scipy,anntzer/scipy,perimosocordiae/scipy,perimosocordiae/scipy,matthew-brett/scipy,tylerjereddy/scipy,mdhaber/scipy,andyfaff/scipy,zerothi/scipy,vigna/scipy,mdhaber/scipy,perimosocordiae/scipy,scipy/scipy,ilayn/scipy,WarrenWeckesser/scipy,vigna/scipy,Stefan-Endres/scipy,perimosocordiae/scipy,mdhaber/scipy,e-q/scipy,endolith/scipy,WarrenWeckesser/scipy,grlee77/scipy,matthew-brett/scipy,anntzer/scipy,ilayn/scipy,endolith/scipy,Stefan-Endres/scipy,anntzer/scipy,Stefan-Endres/scipy,anntzer/scipy,zerothi/scipy,scipy/scipy,scipy/scipy,Eric89GXL/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,andyfaff/scipy,mdhaber/scipy,perimosocordiae/scipy,rgommers/scipy