DOC: spatial: Correct barycentric coordinate description in spatial.Delaunay docstring (#16667)
DOC: spatial: Correct barycentric coordinate description in spatial.Delaunay docstring (#16667)

The third point is on an edge rather than a vertex.
This makes only 1 coordinate null, rather than 2 null coordinates.
scipy/scipy,anntzer/scipy,Stefan-Endres/scipy,mdhaber/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,anntzer/scipy,scipy/scipy,andyfaff/scipy,Stefan-Endres/scipy,rgommers/scipy,WarrenWeckesser/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,rgommers/scipy,mdhaber/scipy,andyfaff/scipy,endolith/scipy,Stefan-Endres/scipy,scipy/scipy,WarrenWeckesser/scipy,perimosocordiae/scipy,andyfaff/scipy,ilayn/scipy,scipy/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,perimosocordiae/scipy,mdhaber/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,andyfaff/scipy,anntzer/scipy,anntzer/scipy,ilayn/scipy,endolith/scipy,endolith/scipy,andyfaff/scipy,mdhaber/scipy,endolith/scipy,WarrenWeckesser/scipy,ilayn/scipy,rgommers/scipy,endolith/scipy,rgommers/scipy,WarrenWeckesser/scipy,rgommers/scipy,endolith/scipy,anntzer/scipy,ilayn/scipy,perimosocordiae/scipy,ilayn/scipy,scipy/scipy,ilayn/scipy,mdhaber/scipy,andyfaff/scipy,mdhaber/scipy,scipy/scipy,anntzer/scipy