Closes #862

What does this change?

I removed the attempt to get the media ID using the non-existent mid field:

$media_id = $file->_referringItem?->getParent()?->getParent()?->getEntity()?->get('mid')?->getString();
$media = $media_id ? Media::load($media_id) : NULL;

Instead, I directly check if the entity is a Media entity:

$entity = $file->_referringItem?->getParent()?->getParent()?->getEntity();
$media = ($entity instanceof \Drupal\media\MediaInterface) ? $entity : NULL;

This change eliminates the need to get the media ID and then load the media entity again. It directly uses the entity if it's already a Media entity, which is more efficient and avoids the error with the non-existent mid field.

Thanks to Big Blue Door for sponsoring my time to work on this.