get_extension_funcs extension parameter does not need to be lowercase

### Affected page

https://www.php.net/manual/en/function.get-extension-funcs.php

### Issue description

> This parameter must be in lowercase.

This is no longer true. The parameter is case-insensitive.

https://news-web.php.net/php.internals/132226

### Steps to reproduce

_No response_

### Suggested fix

_No response_