misc: PHP type hint

hwe/sammo/Event/Action.php

@@ -20,6 +20,7 @@ abstract class Action{
         }
 
         $args = array_slice($actionArgs, 1);
+        /** @var \ReflectionClass<Action> */
         $ref = new \ReflectionClass($className);
         return $ref->newInstanceArgs($args);
     }