Do not override nodeset for stable scenario jobs

It's partial revert of [1], we manage nodeset for
scenario jobs in job neutron-tempest-plugin-base-nested-switch,
which is already nested-virt-focal. So we don't need to
override in individual jobs as with that these jobs
using non nested virt nodes.

[1] https://review.opendev.org/c/openstack/neutron-tempest-plugin/+/861510

Change-Id: I0c9b276411ec0804b18678532b972365c044ca21
5 files changed