Users: When determining whether to show the reassign content option during...

Users: When determining whether to show the reassign content option during user delete, don't rely upon `WP_Query` as it doesn't return all forms of content `wp_delete_user()` operates on.

This restores the reassign form when a user has a non-public post type or links assigned to them.

Props swissspidy & tharsheblows for initial patches.
Fixes #34993 for trunk.

Built from https://develop.svn.wordpress.org/trunk@36068


git-svn-id: https://core.svn.wordpress.org/trunk@36033 1a063a9b-81f0-0310-95a4-ce76da25c4cd