MariaDB version is reported differently between PHP versions:
* PHP 8.0.16 or later: `10.6.8-MariaDB`
* PHP 8.0.15 or earlier: `5.5.5-10.6.8-MariaDB`
The latter includes PHP 7.4.x and PHP 5.6.x as well, where the version is also reported with the `5.5.5-` prefix.
This commit makes an adjustment to the `Tests_DB_Charset` class to check for the correct version.
References:
* [https://github.com/php/php-src/issues/7972 php-src: #7972: MariaDB version prefix 5.5.5- is not stripped]
* [https://github.com/php/php-src/pull/7963 php-src: PR #7963 Fix GH-7932: MariaDB version prefix not always stripped]
Follow-up to [53918].
Fixes#53623.
git-svn-id: https://develop.svn.wordpress.org/trunk@53919 602fd350-edb4-49c9-b593-d223f7449a82