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).

Fewer lines almost always better.  Also, we don't want to spread
these out unless we have to.

... we'll need this later for the TLS cert.

I was about to make a new repository and complicate CI shell scripts to check
it out in the right place at the right time ... but why?

update the localdev grid's secrets and other configuration to reflect this

testing and production are broken by this commit since they have not been
updated similarly

There is no swap to use but (a) try the setting anyway and (b) maybe there
will be at some point.

we deleted it already but it got brought back

Also this no longer needs to be rec

It is no longer required to add IP addresses to the Vagrant-generated ssh
configuration because the Vagrant-configured hostnames now match up with the
names morph will try to use to connect to the VMs.

Just require hostName and domain instead of an extra publicIPv4 option.  Leave
behind a similar option, `publicAddress`, just in case it needs to be
overridden at some point, but stop supplying a value for it anywhere.