This removes the usage of dbType from keyserver's db_config.js file. This is no longer necessary and we plan on upgrading from mariadb10.8 to 10.11.
There is a warning that we're supplying dbType as a mariadb configuration option that doesn't exist (as db-config.js now contains a field we don't use), but looks like devs can just manually remove dbType to remove this warning after this is landed