Kayobe overcloud introspection data save fails because the dynamic
inventory script siliently breaks causing Ansible to parse it as a
static inventory file. The failure occurs due to OS_TOKEN being set.
This change works around setting OS_TOKEN before running the dynamic
inventory script by setting OS_CLOUD before querying inspector.
Confirmed on Stein and Train, and verified in both environments.
Story: 2007326
Task: 38846
Change-Id: I57fbf91ae3440d3e4e6a64cd7d05151e299c9322
