The nixpkgs-unstable channel's programs.sqlite was used to identify
packages producing exactly one binary, and these automatically added
to their package definitions wherever possible.
We need the latest gox to support the latest go releases better.
Unfortunately the author doesn't seem interesting in making new releases
(1y already since the last release).
After #16017 there were a lot
of comments saying that `nix` would be better than `JSON`
for Go packages dependency sets.
As said in https://github.com/NixOS/nixpkgs/pull/16017#issuecomment-229624046
> Because of the content-addressable store, if two programs have the
> same dependency it will already result in the same derivation in
> the
> store. Git also has compression in the pack files so it won't make
> much difference to duplicate the dependencies on disk. And finally
> most users will just use the binary builds so it won't make any
> differences to them.
This PR removes `libs.json` file and puts all package dependencies in
theirs `deps.json`.
