Consume kata-deploy as part of the kata-containers (kubernetes) CI

[fidencio]

kata-containers Kubernetes CI could take advantage of the "latest" kata-deploy image (please, see: https://github.com/kata-containers/kata-containers/issues/1710), consuming it and smartly only updating the needed bits according to the PR being raised.

For instance, considerind we habe a kata-deploy image with the latest merged commit, whenever CI is triggered, we could simply check:

• Did the kernel code change between the latest kata-deploy image and the current PR?
  • If not, do not build the kernel;
• Did the qemu code change between the latest kata-deploy image and the current PR?
  • If not, do not build QEMU;
• Did the agent code change between the latest kata-deploy image and the current PR?
  • If not, do not build the rootfs image;

And those could save a huge amount of CI time (and money).

[GabyCT]

@fidencio can we close this issue? or is still relevant