feat: extra array check is not needed

Author: kristos80

src/Hook.php

@@ -42,10 +42,6 @@ public function addFilter(array|string $hookNames, callable $callback, int $prio
 			$hookNames = [$hookNames];
 		}
 
-		if(!is_array($hookNames)) {
-			throw new InvalidArgumentException("'\$hookNames' should be a string or an array");
-		}
-
 		foreach($hookNames as $hookName) {
 			$this->filters[$hookName] = $this->filters[$hookName] ?? [];
 			$this->filters[$hookName]["callbacks"][$priority] = $this->filters[$hookName]["callbacks"][$priority] ?? [];