[GIT-PULLS] [php-src] PR #22630: ext/dom: Fix Dom\DtdNamedNodeMap index overflow in dimension access

Pull Request: https://github.com/php/php-src/pull/22630
Author: LamentXU123

Dom\DtdNamedNodeMap dimension access could overflow the index when reading DTD entities or notations.

```php
<?php
$doc = Dom\XMLDocument::createFromString("<!DOCTYPE root [<!ENTITY e 'x'>]><root/>");

var_dump($doc->doctype->entities[4294967296]?->nodeName);
```
```
string(1) "e"
```