Find a way to minimize the closure size of our deployments.

We should minimize the amount of software deployed on our servers, in particular, including GUI libraries.

From @jcalderone on https://whetstone.privatestorage.io/privatestorage/PrivateStorageio/-/merge_requests/182#note_16061

I see there is a sibling config option, x11, which defaults to true. Maybe we can cut down the closure size by setting it to false. This could also be fine as a follow-up. I don't think this changeset adds any x11 dependencies (at least not according to diff-closures).

and https://whetstone.privatestorage.io/privatestorage/PrivateStorageio/-/merge_requests/182#note_16134

I'm not sure if there's a way to disable all GUI dependencies at once but a related idea might be having a safety net - we could probably have some part of the system fail loudly if it discovers some basic GUI stuff has made its way into our closure (eg libX11 or something similar). Then at least someone would have to stop and fix the issue before proceeding...

A different (maybe complementary) approach could be to have the closure size of various expressions tracked by a monitoring system? Then we can see how we're doing over time, and maybe understand contributing factors other than GUI stuff.