Rename kubvirt test VMs to fix upgrades from 1.1.1

What does this MR do and why?

Tests of upgrade-from-1.1.1 are failing because cirros VM status is not progressing:

  status:
    conditions:
    - lastProbeTime: null
      lastTransitionTime: "2024-10-20T21:35:47Z"
      status: "True"
      type: Ready
    - lastProbeTime: null
      lastTransitionTime: null
      status: "True"
      type: LiveMigratable
    - lastProbeTime: null
      lastTransitionTime: "2024-10-20T22:07:56Z"
      message: a non-live-updatable field was changed in the template spec
      status: "True"
      type: RestartRequired
    created: true
    desiredGeneration: 2
    observedGeneration: 1

This is very likely to be caused by the update of the cirros image:

!2752 (merged)

As a quick fix (and an alternative to revert that change), I propose to rename the VMs, so that the cirros VM will be re-created.

I've created a follow-up issue to track the need to properly configure the machines to support volume-migration:

#1788 (closed)

Related reference(s)

Closes: #1780 (closed)