[php-src] Issue #10234: Setting DOMAttr::textContent results in an empty attribute value.

Issue: https://github.com/php/php-src/issues/10234 Author: ThomasWeinert ### Description The following code: ```php <?php $document = new DOMDocument(); $document->loadXML('<element attribute="value"/>'); $attribute = $document->documentElement->getAttributeNode('attribute'); // output loaded attribute value var_dump($attribute->textContent); // change value $attribute->textContent = 'new value'; // output changed value var_dump($attribute->textContent); ``` Resulted in this output: ``` string(5) "value" string(0) "" ``` But I expected this output instead: ``` string(5) "value" string(9) "new value" ``` https://3v4l.org/ouRV0 This work in PHP Versions 5.6.1 to 5.6.13, it is broken for any PHP version after that. ### PHP Version PHP 8.2.1 ### Operating System _No response_