Any plugin that declares 'jquery' as a dependency rather than 'jquery-core' will cause jQuery Migrate to be registered too. When we know that all theme & plugin JS is compatible with the latest release of jQuery then we can safely deregister jQuery Migrate.

deregister-jquery-migrate.inc.php

<?php
/**
 * Plugin Name:     eggMUP: Deregister jQuery Migrate
 * Plugin URI:      https://gist.github.com/ianpegg/5aa9524ea2251ba8f3afc1ba56041616
 * Description:     Improve WP performance by removing jQuery Migrate if it isn't needed.
 * Version:         1.0.1
 * Author:          Ian Pegg
 * Author URI:      https://eggcupwebdesign.com
 * php version 8.2.14
 * 
 * @category Must_Use_Plugin
 * @package  WordPress_Plugin
 * @author   Ian Pegg <[email protected]>
 * @license  GNU/GPLv3 https://www.gnu.org/licenses/gpl-3.0.txt
 * @link     https://eggcupwebdesign.com
 */

namespace EggCup\MUP\DeregisterJqueryMigrate;

if (!defined('ABSPATH')) {
    exit;
}


/**
 * Any plugin that declares 'jquery' as a dependency rather than
 * 'jquery-core' will cause jQuery Migrate to be registered too.
 * When we know that all theme & plugin JS is compatible with the 
 * latest release of jQuery then we can safely deregister jQuery Migrate.
 * 
 * @param Array $Arr_scripts All scripts currently registered.
 * 
 * @return void
 */
add_action('wp_default_scripts', function ( $Arr_scripts ) {
    if (!is_admin() && !empty($Arr_scripts->registered['jquery'])) {
        $Arr_scripts->registered['jquery']->deps = array_diff(
            $Arr_scripts->registered['jquery']->deps,
            [ 'jquery-migrate' ]
        );
    }
});