treewide: pkgs.pkgconfig -> pkgs.pkg-config, move pkgconfig to alias.nix

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.

pkgs/applications/editors/emacs/generic.nix

@@ -7,7 +7,7 @@
   , patches ? [ ]
 }:
 { stdenv, lib, fetchurl, fetchpatch, ncurses, xlibsWrapper, libXaw, libXpm
-, Xaw3d, libXcursor,  pkgconfig, gettext, libXft, dbus, libpng, libjpeg, libungif
+, Xaw3d, libXcursor,  pkg-config, gettext, libXft, dbus, libpng, libjpeg, libungif
 , libtiff, librsvg, gconf, libxml2, imagemagick, gnutls, libselinux
 , alsaLib, cairo, acl, gpm, AppKit, GSS, ImageIO, m17n_lib, libotf
 , jansson, harfbuzz
@@ -92,7 +92,7 @@ let emacs = stdenv.mkDerivation (lib.optionalAttrs nativeComp {
     ""
   ];
 
-  nativeBuildInputs = [ pkgconfig makeWrapper ]
+  nativeBuildInputs = [ pkg-config makeWrapper ]
     ++ lib.optionals srcRepo [ autoreconfHook texinfo ]
     ++ lib.optional (withX && (withGTK3 || withXwidgets)) wrapGAppsHook;
 

pkgs/applications/editors/emacs/macport.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, ncurses, pkgconfig, texinfo, libxml2, gnutls, gettext, autoconf, automake, jansson
+{ lib, stdenv, fetchurl, ncurses, pkg-config, texinfo, libxml2, gnutls, gettext, autoconf, automake, jansson
 , AppKit, Carbon, Cocoa, IOKit, OSAKit, Quartz, QuartzCore, WebKit
 , ImageCaptureCore, GSS, ImageIO # These may be optional
 }:
@@ -30,7 +30,7 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
-  nativeBuildInputs = [ pkgconfig autoconf automake ];
+  nativeBuildInputs = [ pkg-config autoconf automake ];
 
   buildInputs = [ ncurses libxml2 gnutls texinfo gettext jansson
     AppKit Carbon Cocoa IOKit OSAKit Quartz QuartzCore WebKit