Cron should not require a Physical Volume Claim

[alecthomas]

The Raft implementation may not support this yet, but because cron does not strictly need a PV, we should remove this requirement to reduce operational complexity.

[jvmakine]

It seems that Raft is not very well suited for ephemeral storage, and we will need to rethink if we are going to use raft here at all. This is a larger architectural discussion we will talk about at our upcoming onsite in 2 weeks in more detail. Will pause this until then.