Systemd sets soft limits by using a <soft:hard> range, see
https://github.com/systemd/systemd/pull/1994. We want soft
and hard limit to be the same, so we use the IMO defective
former behavior of setting the limit once and have systemd
set both. RedHat Bug 1351415 has more informatin about not
being able to set soft limits within the systemd config in
before https://bugzilla.redhat.com/show_bug.cgi?id=1351415

... so we can actually catch the boot loader menu from IPMI on the first try.
Resolving privatestorage/privatestorageops#329 .

Re-importing the path probably breaks other stuff.  Anyway, we only have one
overlay now so this short/simpler thing works.

Rely on upstream package to supply typing and challenge-bypass-ristretto as
necessary.  Simplify our expression (approximately pointfree style) so we
don't have to know about any other arguments that might be passed or accepted.

I don't know

When it changes we often have to rebuild ghc ... :(

Also configure a new value on the staging grid

This removes the code that might delete a Tahoe-LAFS nodedir and replaces it
with code that will try to save an unexpected copy of it out of the way
instead.