[php-src] PR #24422: Fix glob() not negating bracket expressions that start with "^"

Pull Request: https://github.com/php/php-src/pull/24422 Author: nicolas-grekas Since #18164, glob() uses the bundled implementation on all platforms. That implementation negates a bracket expression only when it starts with !. Before, on Linux, the system glob() also negated [^a]. Since 8.5, ^ is a literal there: ```php // in a directory that contains the files a, b and ^ glob('[^a]'); // 8.4 on Linux: ['^', 'b'], 8.5: ['^', 'a'] ``` POSIX leaves [^...] unspecified, but glibc and our own fnmatch() implementation treat it like [!...]. This PR does the same in glob(). On Windows, [^a] now negates too, like fnmatch() already does there. Found while working on symfony/symfony#67133.