[php-src] Issue #10054: DateTime::ISO8601_EXPANDED throws a Fatal error

Issue: https://github.com/php/php-src/issues/10054 Author: miguelitomola ### Description The following code: ```php echo DateTime::ISO8601_EXPANDED; <?php ``` Resulted in this output: ``` Fatal error: Uncaught Error: Undefined constant DateTime::ISO8601_EXPANDED in (path/to/line) ``` But I expected this output instead: ``` X-m-d\TH:i:sP ``` I assummed that constant was available as it's described in the [DateTime class](https://www.php.net/manual/en/class.datetime.php). I have checked other constats from DateTime such as ISO8601 and they all returned the expected value. ### PHP Version 8.1.13 ### Operating System Linux Mint 21 Vanessa base: Ubuntu 22.04 jammy