Fix #109171: Delete curve instead of creating empty result

If accumulated amount of points is zero, next offsets
will be empty too. Instead to expand offsets to create
empty curve, just delete source curve and skip any next steps.

Pull Request: https://projects.blender.org/blender/blender/pulls/109172

source/blender/nodes/geometry/nodes/node_geo_duplicate_elements.cc

@@ -329,6 +329,12 @@ static void duplicate_curves(GeometrySet &geometry_set,
     dst_curves_num += count;
     dst_points_num += count * points_by_curve[selection[i_curve]].size();
   }
+
+  if (dst_points_num == 0) {
+    geometry_set.remove_geometry_during_modify();
+    return;
+  }
+
   curve_offset_data.last() = dst_curves_num;
   point_offset_data.last() = dst_points_num;