Fix: Invalid default value for vert_face_set_get with empty Span

The default value is expected to be 0, not INT_MIN

Pull Request: https://projects.blender.org/blender/blender/pulls/127628

source/blender/editors/sculpt_paint/sculpt.cc

@@ -311,7 +311,7 @@ int vert_face_set_get(const GroupedSpan<int> vert_to_face_map,
                       const Span<int> face_sets,
                       const int vert)
 {
-  int face_set = std::numeric_limits<int>::lowest();
+  int face_set = SCULPT_FACE_SET_NONE;
   for (const int face : vert_to_face_map[vert]) {
     face_set = std::max(face_sets[face], face_set);
   }