Fix T87474: Face Set visibility updates failing with single face loop

Face set visibility is already flushed to all mesh elements in the right
way in SCULPT_visibility_sync_all_face_sets_to_vertices, calling
BKE_mesh_flush_hidden_from_verts is legacy code from the previous
visibility system that was causing the vertex visibility to take
priority over face sets. When hidding a single loop, all vertices of
those faces are still visibile, so this line was tagging all loop faces
visible. This was leaving mesh/face set visibiltiy in an unconsistent
state.

Reviewed By: JacquesLucke

Maniphest Tasks: T87474

Differential Revision: https://developer.blender.org/D11008

source/blender/editors/sculpt_paint/sculpt_face_set.c

@@ -949,10 +949,6 @@ static int sculpt_face_sets_change_visibility_exec(bContext *C, wmOperator *op)
 
   MEM_SAFE_FREE(nodes);
 
-  if (BKE_pbvh_type(pbvh) == PBVH_FACES) {
-    BKE_mesh_flush_hidden_from_verts(ob->data);
-  }
-
   SCULPT_tag_update_overlays(C);
 
   return OPERATOR_FINISHED;