WordPress - Disable Admin Notification of User Password Change

plugin.php

<?php

/**
 * Disable Admin Notification of User Password Change
 *
 * Credit: https://wordpress.stackexchange.com/a/266006/67466
 *
 * Suppressing this email notification has to be handled
 * with a plugin because pluggable.php is loaded earlier
 * than a theme's functions.php file.
 *
 * @see pluggable.php
 */
if ( ! function_exists( 'wp_password_change_notification' ) ) {
    function wp_password_change_notification( $user ) {
        return;
    }
}