Stop trying to hit a specific directory with mktemp

Closes #68

See merge request privatestorage/PrivateStorageio!124

Just use the configured temporary directory in the environment.  This is less
great but it's still okay because:

* It's our system
* The deploy key has limited capabilities

Add GSuite SSO to Grafana

See merge request privatestorage/PrivateStorageio!120

At least it's easy to turn on

This is used in constructing the Google OAuth2 login callback URL and has to
match what's configured in Google - also helps if it is actually the address
of the server.

This should let it work for both enabled and disabled configurations

Upgrade all hosts to release2105 NixOS

Closes privatestorageops#362, privatestorageops#279, and #42

See merge request privatestorage/PrivateStorageio!121

Using AWS is what causes it so using AWS can be what fixes it, too.

The old version of nixpkgs let us get away with setting neither isNormalUser
nor isSystemUser but setting all of the things a normal user would get
directly.  The new version of nixpkgs demands one of these flags be set.  So,
set it, and remove all of the redundant settings that it implies.

Continuous deployment for the grid systems

See merge request privatestorage/PrivateStorageio!115

I hope I'm almost done with this branch.

... This breaks the tie, thx to https://github.com/DBCDK/morph/issues/146

... that don't have it by default. (<5.6)

This was supposed to reduce evaluation-time memory enough to let low-memory
staging servers self-deploy.  But it didn't.

This makes wireguard work on older kernels (19.09 nixos), i.e.
our storage servers currently) and newer kernels (21.05, i.e.
the monitoring server).