Shortcode para inserir scripts externos na edição do post WordPress

wp_shortcode_script.php

<?php

function register_shortcode_script() {
  
  add_shortcode('script', function($src) {
    
    extract(shortcode_atts(array(
        'src' => 'src'
    ), $src));

    return "<script src=\"$src\"></script>";
  });
}
add_action( 'init', 'register_shortcode_script');