continuation of #109595
pkgconfig was aliased in 2018, however, it remained in
all-packages.nix due to its wide usage. This cleans
up the remaining references to pkgs.pkgsconfig and
moves the entry to aliases.nix.
python3Packages.pkgconfig remained unchanged because
it's the canonical name of the upstream package
on pypi.
unibilium expects to use the `ncursesw6-config` command to find terminfo dirs. Before that would fail & default to some nonexistant TERMINFO_DIRS value (on pure systems at least). This will add `ncurses.out` which is a little bit unfortunate because unibilium is meant as a replacement for ncurses. In the future, we should add a `terminfo` output to ncurses so that other things can use its db without pulling in its libraries & binaries.
Fixes#40404.
Unibilium is a very basic terminfo library. It doesn't depend on curses
or any other library. It also doesn't use global variables, so it should
be thread-safe.
