Probe working_dir needs a default #107
Description
It seems the new readiness probe working dir option is missing a default, which results in errors if not set.
After a flake update I now get the likes of
error: The option `settings.processes.kafka.readiness_probe.exec.working_dir' was accessed but has no value defined. Try setting the option.
And this is for a process with no readiness_probe defined.