Do not configure system-scope admin for keystone

This patch removes a couple of tempest.conf settings that are being
overwrriten when Keystone is set to enforce scope.

These settings are already being set by the keystone devstack plugin [1]
and do not need to be overwritten here.

Keystone is changing the default admin credentials to be project-admin
instead of system-admin to address some failing tests in services that
require project-scoped admin for their admin APIs. [2]  These overrides
are preventing that change from taking effect.

[1] https://opendev.org/openstack/keystone/src/branch/stable/2024.1/devstack/lib/scope.sh#L24-L25
[2] https://review.opendev.org/c/openstack/keystone/+/913999

Change-Id: I48edbcbaa993f2d1f35160c415986d21a15a4999

lib/tempest

@@ -702,8 +702,6 @@ function configure_tempest {
     # test can be run with scoped token.
     if [[ "$KEYSTONE_ENFORCE_SCOPE" == True || "$ENFORCE_SCOPE" == True ]] ; then
         iniset $TEMPEST_CONFIG enforce_scope keystone true
-        iniset $TEMPEST_CONFIG auth admin_system 'all'
-        iniset $TEMPEST_CONFIG auth admin_project_name ''
     fi
 
     if [[ "$NOVA_ENFORCE_SCOPE" == True || "$ENFORCE_SCOPE" == True ]] ; then