chore: add Requires PHP header

Author: dannyvankooten

boxzilla.php

@@ -8,7 +8,7 @@
 Author: ibericode
 Author URI: https://www.ibericode.com/
 Text Domain: boxzilla
-Domain Path: /languages/
+Requires PHP: 7.4
 License: GPL-3.0-or-later
 License URI: http://www.gnu.org/licenses/gpl-3.0.html