Stop relying on VCPU count in the introspection tests

Starting with Rocky bare metal nodes no longer expose VCPU/DISK/RAM,
just use hypervisor count instead.

Change-Id: I792d1e04dc9d98341f9ee8106507afd43c980187
diff --git a/ironic_tempest_plugin/tests/scenario/introspection_manager.py b/ironic_tempest_plugin/tests/scenario/introspection_manager.py
index eb31327..21b9911 100644
--- a/ironic_tempest_plugin/tests/scenario/introspection_manager.py
+++ b/ironic_tempest_plugin/tests/scenario/introspection_manager.py
@@ -201,8 +201,7 @@
         while True:
             time.sleep(CONF.baremetal_introspection.hypervisor_update_sleep)
             stats = self.hypervisor_stats()
-            expected_cpus = self.baremetal_flavor()['vcpus']
-            if int(stats['hypervisor_statistics']['vcpus']) >= expected_cpus:
+            if int(stats['hypervisor_statistics']['count']):
                 break
 
             timeout = CONF.baremetal_introspection.hypervisor_update_timeout