We want to replace the current executors with focal executors.
Make sure zuul-executor can run there.
Kubic is apparently the new source for libcontainers stuff:
https://podman.io/getting-started/installation.html
Use only timesyncd on focal
ntp and timesyncd have a hard conflict with each other. Our test
images install ntp. Remove it and just stay with timesyncd.
Change-Id: I0126f7c77d92deb91711f38a19384a9319955cf5