Blender Git Loki

Fix T75968: PBVH raycast returns wrong active vertex

nearest_vertex_co was not reset when a new triangle was intersected by
the ray, so it was always returning the closest vertex to the real
cursor position in any triangle, which was not always the triangle under
the cursor.

Reviewed By: sergey

Maniphest Tasks: T75968

Differential Revision: https://developer.blender.org/D7485