💚 Fix CI failure due to missing function stubs

Author: stracker-phil

tests/PHPUnit/bootstrap.php

@@ -4,6 +4,7 @@
 define('TESTS_ROOT_DIR', dirname(__DIR__));
 define('ROOT_DIR', dirname(TESTS_ROOT_DIR));
 
+require_once TESTS_ROOT_DIR . '/inc/wp_functions.php';
 require_once ROOT_DIR . '/vendor/autoload.php';
 require_once TESTS_ROOT_DIR . '/stubs/WC_Payment_Gateway.php';
 require_once TESTS_ROOT_DIR . '/stubs/WC_Payment_Gateway_CC.php';