[php-src] Issue #9069: The order of `$encodings` parameter in `mb_detect_encoding()` is sometimes ignored

Issue: https://github.com/php/php-src/issues/9069 Author: machitgarha ### Description The PHP documentation says: > #### $encodings > > A list of character encodings to try, **in order**. The list may be specified as an array of > strings, or a single string separated by commas. But in PHP 8.1, it *may* not be regarded. The following code: ```php echo mb_detect_encoding('$x + 2', ['UTF-7', 'UTF-8']) . PHP_EOL; echo mb_detect_encoding('$x + 2', ['UTF-8', 'UTF-7']) . PHP_EOL; ``` Resulted in this output: ``` UTF-7 UTF-7 ``` But I expected this output instead: ``` UTF-7 UTF-8 ``` Maybe related to #9008, but I felt like opening a new one is better. ### PHP Version PHP 8.1.8 ### Operating System Fedora Workstation 36