This reverts commit 095fe5b43def40279a243e663c662b02caac5318.
Pointless renames considered harmful. All they do is force people to
spend extra work updating their configs for no benefit, and hindering
the ability to switch between unstable and stable versions of NixOS.
Like, what was the value of having the "nixos." there? I mean, by
definition anything in a NixOS module has something to do with NixOS...
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.