podvm-mkosi: startup time in comparison to packer-builds

[mkulke]

On Azure, a mkosi-backed podvm currently takes considerably longer (>30s) to start a pod than the images that are build w/ packer based on ubuntu 22.04 + cloud-init.

This should be observable when toggling between packer-based and mkosi podvm images in the peerpod configuration.

We want to figure out what the culprit is, we can use systemd analyze and cloud-init analyze

It's possible that the mkosi instance is only reported as ready later in the boot process and hence CAA will not start to initiatie connections, as it waits for the create-vm call to return.