[php-src] Issue #9950: DateTime modify does not work with addition of minus values

Issue: https://github.com/php/php-src/issues/9950 Author: shyim ### Description The following code: ```php <?php $a = (new \DateTimeImmutable('2022-05-01 22:00:00'))->modify('+-30 seconds'); var_dump($a); ``` Resulted in this output: ``` Adds 30 seconds ``` But I expected this output instead: ``` Should remove 30 seconds like before ``` https://3v4l.org/6eMQj It did work before RC3. I am not sure if this is intended or not 😅 ### PHP Version PHP 8.2.0 RC6 ### Operating System macOs Ventura 13.1 Beta 2