It was introduced in c10fe14 but removed in c4f910f.
It remained such that people with older generations in their boot
entries could still boot those. Given that the parameter hasn't had any
use in quite some years, it seems safe to remove now.
Fixes#60184
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.
