Blender Git Loki

Fix T93869: snap cursor may fail in orthographic view

Float precision issues cause the `ED_view3d_win_to_3d_on_plane` to return
a value even when the view ray is parallel to the plane.

A more general solution might be desired in this case, as other areas that
use `ED_view3d_win_to_3d_on_plane` might have the same problem.

For now, just work around the problem for the snap cursor.