How to disable publish_future_post auto add wp_options cron

You could hook pre_schedule_event to stop scheduling them, e.g.

function pre_schedule_event_no_publish_future_post( $result, $event, $wp_error ) {
    if ( $event->hook === 'publish_future_post' ) {
        // Don't schedule this event
        return false;
    }
    return $result;
}
add_filter( 'pre_schedule_event', 'pre_schedule_event_no_publish_future_post', 10, 3 );

You could possibly remove the _future_post_hook call instead

remove_action( 'future_post', '_future_post_hook', 5, 2 );

but I think pre_schedule_event is safer.

However I’d guess there are better ways to set this up too.