Add IndexType definition for Nanoflann KDTree in node_spatial_tree. (ros-navigation#5420)

* fix: Add KDTree type definition to include unsigned int for IndexType

Signed-off-by: Ericsii <ericfengx@foxmail.com>

* code format

Signed-off-by: Ericsii <ericfengx@foxmail.com>

---------

Signed-off-by: Ericsii <ericfengx@foxmail.com>

Author: Ericsii

nav2_route/include/nav2_route/node_spatial_tree.hpp

@@ -55,7 +55,9 @@ struct GraphAdaptor
 };
 
 typedef nanoflann::KDTreeSingleIndexAdaptor<
-    nanoflann::L2_Simple_Adaptor<double, GraphAdaptor>, GraphAdaptor, DIMENSION> kd_tree_t;
+    nanoflann::L2_Simple_Adaptor<double, GraphAdaptor>, GraphAdaptor, DIMENSION,
+    unsigned int>
+  kd_tree_t;
 
 /**
  * @class nav2_route::NodeSpatialTree