OSA playbooks only call this role once for all Ironic containers
(API and inspector). As a result, the wheel builds only happen
once. If the first host (which is responsible for wheel builds)
is an API container, these vars would prevent Ironic inspector
requirements being accounted for, and as such no matching
constraints will be generated.
When the venv is deployed to the Ironic inspector container,
the lack of constraints can cause dependencies which are too new
to be installed, causing the service to fail.
Alternatively this role could be called twice by the playbook
for differing container/host roles, but as inspector is expected
to be merged into ironic at some point this feels equally valid.
Change-Id: I3952a4e5514824381410d87ed6d535f13ec40498
a665f45a69