OK, @lukasz-gorski helped me to fix this problem.
SOLUTION:
do not create this file
/site/config/environments/production.php
instead add
if ( env( 'WP_ROCKET_KEY' ) ) {
define( 'WP_ROCKET_KEY', env( 'WP_ROCKET_KEY' ) );
}
// Your email, the one you used for the purchase.
if ( env( 'WP_ROCKET_EMAIL' ) ) {
define( 'WP_ROCKET_EMAIL', env( 'WP_ROCKET_EMAIL' ) );
}
define('WP_CACHE', true);
to the bottom of /site/config/application.php
then add
wp_rocket_key: {insert_wp_rocket_key_here}
wp_rocket_email: {insert_wp_rocket_email_here}
to group_vars/all/vault.yml
this will allow you to deploy production with wp-rocket