PHP warning regarding filemtime()

I’m on Slim SEO 4.11.2. Every admin screen throws this warning:

filemtime(): stat failed for wp-content/plugins/slim-seo/js/redirection/deleted-url-notification.js in slim-seo/src/Redirection/DeletedURLNotification.php on line 90

DeletedURLNotification::enqueue() runs on admin_enqueue_scripts and calls filemtime() on that path. The file is not in the plugin zip. The redirection script that is included is js/build/redirection.js.

The warning shows even when there are no deleted-URL notices, because enqueue() does not check that the file exists first.

Can you ship that file, or skip the filemtime() call when it is missing? Thank you!