Improve Twig security policy

Follow up to 106daa2...7cb148c. Thanks to @ka1n4t for the additional review.

Author: LukeTowers

modules/system/twig/SecurityPolicy.php

@@ -20,6 +20,8 @@ final class SecurityPolicy implements SecurityPolicyInterface
     protected $blockedMethods = [
         'addDynamicMethod',
         'addDynamicProperty',
+        'bindEvent',
+        'bindEventOnce',
     ];
 
     /**