Mike we'll have newer MariaDB (and possibly MySQL) available when we start rolling out new servers with a newer operating system some time in 2023.
If you follow the private instance procedure here in the forum you'll be running the same version of MariaDB as the system version, as that procedure is not a completely separate installation but a separate instance of the existing software running with local config.
For now if you need a newer version you'll need to download a binary release or build it from source and then run that as a custom application.