[php-src] Issue #23057: ext/DOM Fails to build on php8.5

Issue: https://github.com/php/php-src/issues/23057
Author: bigfoot90

### Description

The following code:

```dockerfile
FROM php:8.5-fpm-alpine

RUN apk add --no-cache libxml2-dev
RUN docker-php-ext-install dom
```

Resulted in this output:
```
In file included from /usr/src/php/ext/dom/html_document.c:25:
/usr/src/php/ext/dom/html5_parser.h:21:10: fatal error: lexbor/html/parser.h: No such file or directory
   21 | #include <lexbor/html/parser.h>
      |          ^~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [Makefile:250: html_document.lo] Error 1
```

But I expected this output instead:
```
```


### PHP Version

```plain
PHP 8.5.9 (cli) (built: Jul 30 2026 22:44:26) (NTS)
Copyright (c) The PHP Group
Built by https://github.com/docker-library/php
Zend Engine v4.5.9, Copyright (c) Zend Technologies
    with Zend OPcache v8.5.9, Copyright (c), by Zend Technologies
```

### Operating System

_No response_