Don't select invisible items in FileSystem dock

editor/filesystem_dock.cpp

@@ -2053,7 +2053,7 @@ Vector<String> FileSystemDock::_tree_get_selected(bool remove_self_inclusion, bo
 	TreeItem *selected = tree->get_root();
 	selected = tree->get_next_selected(selected);
 	while (selected) {
-		if (selected != cursor_item && selected != favorites_item) {
+		if (selected != cursor_item && selected != favorites_item && selected->is_visible_in_tree()) {
 			selected_strings.push_back(selected->get_metadata(0));
 		}
 		selected = tree->get_next_selected(selected);