refactor: remove old files

src/WPDesk/Notice/views/admin-head-js-gutenberg.php

-<?php
-if ( ! defined( 'ABSPATH' ) ) {
-    exit;
-} // Exit if accessed directly
-?>
-<script type="text/javascript">
-    <?php include dirname(__FILE__, 5) . '/assets/js/gutenberg.js'; ?>
-</script>

src/WPDesk/Notice/views/admin-head-js.php

-<?php
-if ( ! defined( 'ABSPATH' ) ) {
-    exit;
-} // Exit if accessed directly
-?>
-<script type="text/javascript">
-    <?php include dirname(__FILE__, 5) . '/assets/js/notice.js'; ?>
-</script>
-<style>.wpdesk-notice-gutenberg { display: none; }</style>