Remove unused code in `AnimationPlayerEditor::_update_animation_list_icons()`

(cherry picked from commit 6a1e3380f86b5231c59ba583c2d50449816f3514)

editor/plugins/animation_player_editor_plugin.cpp

@@ -898,11 +898,6 @@ void AnimationPlayerEditor::_update_player() {
 }
 
 void AnimationPlayerEditor::_update_animation_list_icons() {
-	List<StringName> animlist;
-	if (player) {
-		player->get_animation_list(&animlist);
-	}
-
 	for (int i = 0; i < animation->get_item_count(); i++) {
 		String name = animation->get_item_text(i);