wp-multi-city/includes/class-title-filter.php

<?php
declare(strict_types=1);

namespace WPMultiCity;

final class TitleFilter
{
    public static function register(): void
    {
        \add_filter('the_title', 'do_shortcode', 9999);
        \add_filter('single_cat_title', 'do_shortcode', 9999);
    }
}