Description:
------------
The stub for this method looks like this (https://github.com/php/php-src/blob/4c5e47d113429773a885e78599e20cfe0490905b/ext/dom/php_dom.stub.php#L207-L208):

    /** @return DOMAttr|false */
    public function removeAttributeNode(string $qualifiedName) {}

But the method accepts DOMAttr: https://3v4l.org/dbST3

PHP documentation agrees: https://www.php.net/manual/en/domelement.removeattributenode.php

Originally reported as PHPStan bug: https://github.com/phpstan/phpstan/issues/4268

Test script:
---------------
<?php declare(strict_types = 1);

$document = new DOMDocument();
$document->loadXML('<x a="foo"/>');
/** @var DOMElement $element */
$element = $document->documentElement;
$attribute = $element->getAttributeNode('a');
$element->removeAttributeNode($attribute);
var_dump($document->saveHTML());