Fix icebug-13.2 issues with copy

[adsharma]

ladybug/extension/algo/vendor/include/networkit/graph/GraphIteration.hpp:126:25: note: use reference type to prevent copying
  126 |         for (const auto nb : g.template outNeighbors<Weighted>(u)) {
      |                         ^~
      |                         &
cc1plus: all warnings being treated as errors

https://github.com/LadybugDB/ladybug/actions/runs/33478043787/job/99761343751