I've been trying to find a way to hide/deactivate the Parent dropdown menu from the Posts -> Categories screen.  
`http://example.com/wp-admin/edit-tags.php?taxonomy=category`

I was able to hide the "Slug" option through this function here:

    // Admin - Global Terms Enabled
    function disable_global_terms($enablefalse) {
       return 1;
    }
    add_filter( 'global_terms_enabled', 'disable_global_terms' );

Is there a way I can do the same for the Parent Drop Down menu without deleting that code from the main WP files so I would have to do this each time with each update?