test_vif_attach_node_doesnt_exist and test_vif_detach_no_args fail when shared_physical_network is set to true

[Lukas Piwowarski]

The following two tests:
 - ironic_tempest_plugin.tests.api.admin.test_nodes.TestNodesVif.test_vif_attach_node_doesnt_exist
 - ironic_tempest_plugin.tests.api.admin.test_nodes.TestNodesVif.test_vif_detach_no_args

are failing consistently on:

Traceback (most recent call last):
  File "/usr/lib/python3.9/site-packages/ironic_tempest_plugin/tests/api/admin/test_nodes.py", line 317, in setUp
    self.net = self.os_admin.networks_client.list_networks(
IndexError: list index out of range

when CONF.network.shared_physical_network is set to true. Note, that both tests pass when shared_physical_network == false.

I'm attaching log with the failure and tempest.conf.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/ironic-tempest-plugin/+/919544