WordPress 관리자 알림을 완전히 비활성화하는 방법

<?php
/**
 * Disable Admin Notices WordPress
 * Description: Completely removes all admin notices from the WordPress dashboard,
 * including core WordPress notices and those added by plugins and themes.
 * @author Faisal Ahammad <me@faisalahammad.com>
 */

/**
 * Remove all notice actions
 */
function disable_all_admin_notices() {
    remove_all_actions('admin_notices');
    remove_all_actions('all_admin_notices');
    remove_all_actions('user_admin_notices');
    remove_all_actions('network_admin_notices');
}
add_action('admin_init', 'disable_all_admin_notices', 1);

/**
 * Add CSS to hide notice elements
 */
function hide_admin_notices_css() {
    ?>
    <style>
        .notice, 
        .notice-error, 
        .notice-warning, 
        .notice-success, 
        .notice-info, 
        .updated, 
        .error, 
        .update-nag {
            display: none !important;
        }
    </style>
    <?php
}
add_action('admin_head', 'hide_admin_notices_css', 1);

/**
 * Disable notice output
 */
function return_false() {
    return false;
}
add_action('admin_notices', 'return_false', 1);
add_action('all_admin_notices', 'return_false', 1);
add_action('user_admin_notices', 'return_false', 1);
add_action('network_admin_notices', 'return_false', 1);

/**
 * Remove update nags
 */
function remove_core_update_notices() {
    remove_action('admin_notices', 'update_nag', 3);
    remove_action('admin_notices', 'maintenance_nag', 10);
}
add_action('admin_init', 'remove_core_update_notices', 1);

function disable_all_admin_notices() {
    remove_all_actions('admin_notices');
    remove_all_actions('all_admin_notices');
    remove_all_actions('user_admin_notices');
    remove_all_actions('network_admin_notices');
}

function hide_admin_notices_css() {
    ?>
    <style>
        .notice, 
        .notice-error, 
        .notice-warning, 
        .notice-success, 
        .notice-info, 
        .updated, 
        .error, 
        .update-nag {
            display: none !important;
        }
    </style>
    <?php
}

function remove_core_update_notices() {
    remove_action('admin_notices', 'update_nag', 3);
    remove_action('admin_notices', 'maintenance_nag', 10);
}