test: stop testing the VMs state after attempting shutdown during installation
test: stop testing the VMs state after attempting shutdown during installation

This check was inherently racy, because of https://bugzilla.redhat.com/show_bug.cgi?id=1818089
When we performed the 'destroy' operation on the domain, virt-install
exited and restarted the guest. Thus for a fraction of a second the
state was 'shut off' allowing the test sometimes to pass.

Closes #14340
mvollmer/cockpit,moraleslazaro/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,deryni/cockpit,cockpit-project/cockpit,moraleslazaro/cockpit,moraleslazaro/cockpit,martinpitt/cockpit,garrett/cockpit,mvollmer/cockpit,cockpit-project/cockpit,moraleslazaro/cockpit,martinpitt/cockpit,cockpit-project/cockpit,garrett/cockpit,deryni/cockpit,martinpitt/cockpit,deryni/cockpit,mvollmer/cockpit,garrett/cockpit,cockpit-project/cockpit,moraleslazaro/cockpit,deryni/cockpit,garrett/cockpit,martinpitt/cockpit,deryni/cockpit,garrett/cockpit,mvollmer/cockpit,deryni/cockpit,martinpitt/cockpit,deryni/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit