fix: clears dir nav map between rebuilds

Author: kfc35

crates/bevy_input_focus/src/directional_navigation.rs

@@ -773,6 +773,8 @@ fn auto_rebuild_ui_navigation_graph(
         })
         .collect();
 
+    // clear the old nav map between rebuilds to ensure any removed entities' edges are pruned
+    directional_nav_map.clear();
     auto_generate_navigation_edges(&mut directional_nav_map, &nodes, &config);
 }