We get deprecation warnings from ansible about use
of python2 on xenial hosts. Rather than setting
ansible_python_interpreter to python3 on a host by
host basis, set it globally to python3.
Set it to python for the one host that's too old,
refstack.openstack.org, which is running on trusty
which only has python3.4.
Change-Id: I4965d950c13efad80d72912911bc7099e9da1659
We are starting over with the container nodepool host, and also moving
it to "nb04" to avoid any possibility of conflicting with the
short-hostname of nb01.openstack.org.
Story: #2007407
Task: #39064
Depends-On: https://review.opendev.org/713575
Depends-On: https://review.opendev.org/713571
Change-Id: I18ab9834ad4da201774e0abef56f618cd7839d36