Remove system scope token usage

Octavia supports the system scope and now we are enabling the new defaults
by default that raise an error when system scoped tokens are used.

To enable the new defaults, we need to remove the usage of system
scope token from tests otherwise they fail.

- https://review.opendev.org/c/openstack/octavia/+/925625

Depends-On: https://review.opendev.org/c/openstack/octavia/+/929580
Change-Id: I1bf193807eb254507626b4e7f2bb071ba46d7290
21 files changed