message: Remove bad attribute maybe_unused
  `CGAL_UNUSED` or `[[maybe_unused]]` is useful if we name the argument but don't use it. If we don't name it, the attribute is wrong as it would apply to the type and not the variable.
diff: @@ -139,7 +139,7 @@ class Kd_tree_search {
  }
  template <typename Coord_iterator>
  - bool contains_point_given_as_coordinates(Coord_iterator pi, Coord_iterator CGAL_UNUSED) const {
  + bool contains_point_given_as_coordinates(Coord_iterator pi, Coord_iterator) const {
  FT distance = 0;
  auto ccci = traits.construct_cartesian_const_iterator_d_object();
  auto ci = ccci(c);
  