\Drupal\jsonapi\Controller\FileUpload deprecation layer does not work

This should go into 10.6.x and 10.5.x.

Seems pretty straight forward and does appear to be a typo.

Good catch. If we used \Drupal\file\Upload\FileUploadHandler::class as the service name this would probably have been caught sooner.

larowlan → closed merge request !12456

Committed to 10.6.x and backported to 10.5.x - thanks!