permission_callback is required for register_rest_route()

This route seems OK to make public—this isn't a valid solution for most other things we're doing!

plugins/wp-import-helper.php

@@ -41,6 +41,7 @@
         'callback' => fn() => [
             'pong' => true,
         ],
+        'permission_callback' => '__return_true',
     ]);
 
     register_rest_route('craftcms/v1', 'info', [