Cleanup for imgur uploads does not work

[tipa]

Bug Report

The --map --cleanup command doesn't work for imgur uploads.
It is documented that unused files are detected and can be removed: https://github.com/FriendsOfFlarum/upload#mapfilescommand

Current Behavior
I am prompted if I want to delete a picture, but confirming it with yes does not deleted it.
If I run the command again, the same picture is offered for deletion again

Steps to Reproduce
php flarum fof:upload --map --cleanup --cleanup-before="a month ago"

Expected Behavior
Unused Imgur uploads are detected and can be deleted
Related issue: #290

Environment

• Flarum version: 1.8.3
• Extension version: 1.4.1
• Webserver: apache
• Hosting environment: shared
• PHP version: 8.2.11