Breaking: #72416 - Remove EXT:t3skin/stylesheets/sprites/¶
See Issue #72416
The sprites and related icons from EXT:t3skin/stylesheets/sprites/ have been removed.
References to the sprites or images of EXT:t3skin/ will throw a 404 not found.
Installations or extensions which have references to icons in EXT:t3skin/images/icons/* or EXT:t3skin/stylesheets/sprites/.
No migration, remove all references and use the IconFactory for all icon related stuff.