Modified arg types for `NumberNode::bound_axis_sums()

Added a `const` to `State& state`.

Author: fastbodin

dwave/optimization/include/dwave-optimization/nodes/numbers.hpp

@@ -157,7 +157,7 @@ class NumberNode : public ArrayOutputMixin<ArrayNode>, public DecisionNode {
     /// Return the state-dependent sum of the values within each slice
     /// along each bound axis. The returned vector is indexed by the
     /// bound axes in the same ordering that `axis_wise_bounds()` returns.
-    const std::vector<std::vector<double>>& bound_axis_sums(State& state) const;
+    const std::vector<std::vector<double>>& bound_axis_sums(const State& state) const;
 
  protected:
     explicit NumberNode(std::span<const ssize_t> shape, std::vector<double> lower_bound,

dwave/optimization/src/nodes/numbers.cpp

@@ -448,7 +448,7 @@ const std::vector<NumberNode::AxisBound>& NumberNode::axis_wise_bounds() const {
     return bound_axes_info_;
 }
 
-const std::vector<std::vector<double>>& NumberNode::bound_axis_sums(State& state) const {
+const std::vector<std::vector<double>>& NumberNode::bound_axis_sums(const State& state) const {
     return data_ptr<NumberNodeStateData>(state)->bound_axes_sums;
 }