Revert "Issue #3260173 by andregp, joachim, tstoeckler, nod_: Media should set the owner field to anonymous if no explicit owner is set"

This reverts commit 7aa35b3fec.

(cherry picked from commit 6415ee9b7a)

core/modules/media/src/Entity/Media.php

@@ -458,7 +458,6 @@ class Media extends EditorialContentEntityBase implements MediaInterface {
 
     $fields['uid']
       ->setLabel(t('Authored by'))
-      ->setRequired(TRUE)
       ->setDescription(t('The user ID of the author.'))
       ->setRevisionable(TRUE)
       ->setDisplayOptions('form', [