wp-rocket-disable-permissions-warnings.php

<?php
/**
 * Plugin Name: WP Rocket | Disable permissions warnings about "cache" folders
 * Description: It will prevent WP Rocket from displaying warnings on environments where the "cache" folders aren't writeable.
 * Author:      Vasilis Manthos
 * License:     GNU General Public License v3 or later
 * License URI: http://www.gnu.org/licenses/gpl-3.0.html
 */

// Basic security, prevents file from being loaded directly.
defined( 'ABSPATH' ) or die( 'Cheatin&#8217; uh?' );

function wp_rocket_disable_permissions_warnings(){

	remove_action( 'admin_notices', 'rocket_warning_cache_dir_permissions' );
	remove_action( 'admin_notices', 'rocket_warning_minify_cache_dir_permissions' );
	remove_action( 'admin_notices', 'rocket_warning_busting_cache_dir_permissions' );
	
	add_action( 'wp_loaded', function() {
		$container = apply_filters( 'rocket_container', '');
		$container->get('event_manager')->remove_callback( 'admin_notices', [ $container->get('critical_css_subscriber'), 'warning_critical_css_dir_permissions'] );
		} );
}

add_action( 'wp_rocket_loaded', 'wp_rocket_disable_permissions_warnings' );