Use Ironic pxe_ipa job in Nova
Use Ironic pxe_ipa job in Nova

This drops the use of Ironic's pxe_ssh job in Nova, and moves it to use
pxe_ipa instead. This job uses a prebuilt ironic-python-agent ramdisk
from tarballs.o.o (rather than building a dib image from source), and
is really what we want to use anyway, since we're deprecating the bash
ramdisk. This will remain non-voting.

Change-Id: Iae442c9200a5ed4b26e6bee644f0897f98da5b1d

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