take mariadb-connector out of dbapi main job

take mariadb-connector out of dbapi main job

mariadb-connector seems to have their release situation "fixed",
but for 1.1.5post3 they are requiring mariadb-connector-c 3.3.1, Fedora 36
which is quite bleeding edge only has 3.2.7.    There's no way we
can easily have a version specifier that will look at underlying
client libraries.

since mariadb-connector's main branch seems to work way ahead of
where we will normally have client libraries set up, it's not really
worth testing in CI right now.

Change-Id: Idcb034da6d06620b5e212582bbc63a246a9fe58b