Replace deprecated nova::compute::ironic::max_concurrent_builds
Replace deprecated nova::compute::ironic::max_concurrent_builds

Depends-on: https://review.opendev.org/#/c/749925/
Change-Id: Ic5badc36309f57c15eb941a27c8b7601dbdd8cec

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates