Remove unicode constant in form rule (joomla#44662)

Thanks @laoneo ... all gone.

Author: laoneo

libraries/src/Form/FormRule.php

@@ -5,31 +5,16 @@
  *
  * @copyright  (C) 2017 Open Source Matters, Inc. <https://www.joomla.org>
  * @license    GNU General Public License version 2 or later; see LICENSE.txt
- *
- * Remove phpcs exception with deprecated constant JCOMPAT_UNICODE_PROPERTIES
- * @phpcs:disable PSR1.Files.SideEffects
  */
 
 namespace Joomla\CMS\Form;
 
+// phpcs:disable PSR1.Files.SideEffects
 \defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
 
 use Joomla\Registry\Registry;
 
-// Detect if we have full UTF-8 and unicode PCRE support.
-if (!\defined('JCOMPAT_UNICODE_PROPERTIES')) {
-    /**
-     * Flag indicating UTF-8 and PCRE support is present
-     *
-     * @const  boolean
-     * @since  1.6
-     *
-     * @deprecated  4.0 will be removed in 6.0
-     *              Will be removed without replacement (Also remove phpcs exception)
-     */
-    \define('JCOMPAT_UNICODE_PROPERTIES', (bool) @preg_match('/\pL/u', 'a'));
-}
-
 /**
  * Form Rule class for the Joomla Platform.
  *