[testing] Pin MariaDB version.
[testing] Pin MariaDB version.

alexgibson/lumbergh,glogiotatidis/lumbergh,alexgibson/lumbergh,mozilla/lumbergh,glogiotatidis/lumbergh,mozilla/lumbergh,mozilla/lumbergh,glogiotatidis/lumbergh,mozilla/lumbergh,alexgibson/lumbergh,glogiotatidis/lumbergh,alexgibson/lumbergh