Ironic has maintained a CI job for years after postresql support was
deprecated in order to prevent unintentional breakage of that support.
Now, we have confirmed evidence that other openstack components, such as
keystone, required for testing this postgresql support no longer
function in this job.
As a result, ironic can no longer test postgresql support. Operators
utilizing postgresql who have not yet migrated must migrate now.
Change-Id: If6e4432b000996789346a1f7449410cfc8497fe1
466cd3902c