Make the ironic-parallel job experimental
Make the ironic-parallel job experimental

This job has not been passing in a long time (if ever).

It's in the experimental pipeline for tempest, but the check pipe for
ironic. This patch moves it to ironic's experimental pipeline. We'll
move it back when it has a chance of passing.

Change-Id: I1f36381c7101dfdfaca1eee9aa9ca92c9c4769b8

noorul/os-project-config,openstack-infra/project-config,dongwenjuan/project-config,Tesora/tesora-project-config,openstack-infra/project-config,Tesora/tesora-project-config,dongwenjuan/project-config,noorul/os-project-config