Fix PHPStan errors in monsters.php

phpstan.neon

@@ -29,6 +29,7 @@ parameters:
 		- '#Variable \$[a-zA-Z0-9\\_]+ might not be defined#'
 		# Eloquent models
 		- '#Call to an undefined static method [a-zA-Z0-9\\_]+::[a-zA-Z0-9\\_]+()#'
+		- '#Call to an undefined method object::toArray\(\)#'
 		# system/pages/highscores.php
 		- '#Call to an undefined method Illuminate\\Database\\Query\\Builder::withOnlineStatus\(\)#'
 		- '#Access to an undefined property Illuminate\\Database\\Eloquent\\Model::\$online_status#'