treewide: pkgconfig -> pkg-config

Fix building with `config.allowAliases = false;`.

pkgs/development/r-modules/default.nix

@@ -231,7 +231,7 @@ let
   };
 
   packagesWithNativeBuildInputs = {
-    arrow = [ pkgs.pkgconfig pkgs.arrow-cpp ];
+    arrow = [ pkgs.pkg-config pkgs.arrow-cpp ];
     adimpro = [ pkgs.imagemagick ];
     animation = [ pkgs.which ];
     audio = [ pkgs.portaudio ];