mariadb: remove withoutClient

When used as a global override, it breaks most of the options in the
mysql module, such as ensureDatabases, ensureUsers, initialDatabases,
initialScript.

We could use `.client` there, but if the reasoning behind this was
closure size reduction, we now end up with the same (or a bigger)
runtime closure and more complexity.

Apart from the options exposed by the mysql module, the client is also
likely to be required for local backups or DBA tasks anyways.

Instead of dealing with all the increased complexity of this for no
arguable benefit, let's just remove the `withoutClient` argument.
Storage space on mysql servers shouldn't be that much of an issue.

Closes #82428.