This was causing a few bits of suffering downstream, in particular, in
the NixOS module, which, after this change, can have the
`officialRelease` stuff in *it* completely deleted since we now have
correct defaulting in package.nix for it.
It also eliminates some automated editing of Nix files, which is
certainly always welcome to eliminate.
Fixes: #406
Change-Id: Id12f3018cff4633e379dbfcbe26b7bc84922bdaf
This can release x86_64-linux binaries to staging, with ephemeral keys.
I think it's good enough to review at least at this point, so we don't
keep adding more stuff to it to make it harder to review.
Change-Id: Ie95e8f35d1252f5d014e819566f170b30eda152e