Extended Duration of Integration Tests Run

[so-sahu]

Describe the bug
The integration-tests run time has been increasing steadily, now taking over 20 minutes. It seems that in some of the integration tests, no images are provided, resulting in the need to destroy the machine due to no OS. This, coupled with a high gracefulShutdownTimeout, as seen here, is causing the extended duration of the integration-tests run.

Proposed Solution
To improve the situation, machines should boot properly in integration tests so that the shutdown process can be triggered, ultimately leading to a shorter run duration for the integration tests.

[lukas016]

i did that in this PR: https://github.com/ironcore-dev/libvirt-provider/pull/222/files