Rip out `zfs allow` calls

[DemiMarie]

qubesd runs as root, so they are unnecessary complexity and provide no benefit.

[cfcs]

I had some issues without the allow calls, but it was a while ago, maybe things have changed now.

I'm inclined to keep them until there is a testsuite, if nothing else it makes manual zfs invocations less awkward?

[DemiMarie]

That’s fine; it isn’t a big deal.