[php-src] Issue #18955: strtotime($month) not returning the correct timestamp

Issue: https://github.com/php/php-src/issues/18955 Author: allentcm ### Description The following code: ```php date('n', strtotime('February')) // run on 27 Jun 2025 date('n', strtotime('February')) // run on 30 May 2025 <?php ``` Resulted in this output: ``` "2" "3" ``` But I expected this output instead: ``` "2" "2" ``` https://drive.google.com/file/d/1--9Gvd5jbyfkLE4eHGmddOh4vtBZSfoS/view?usp=sharing https://drive.google.com/file/d/19N0EMOBLTiAXg7G4qgeKeS8kIFlk-DC1/view?usp=sharing https://drive.google.com/file/d/1f5NK9bRJwwU1oL7zkkEMrCdeRiAJ7J5q/view?usp=sharing ### PHP Version ```plain PHP 8.3.19 (cli) (built: Apr 8 2025 03:57:19) (NTS) Copyright (c) The PHP Group Zend Engine v4.3.19, Copyright (c) Zend Technologies with Zend OPcache v8.3.19, Copyright (c), by Zend Technologies ``` ### Operating System _No response_