treewide: clean up 'meta = with' pattern

This commit was created by a combination of scripts and tools:
- an ast-grep script to prefix things in meta with `lib.`,
- a modified nixf-diagnose / nixf combination to remove unused `with
lib;`, and
- regular nixfmt.

Co-authored-by: Wolfgang Walther <walther@technowledgy.de>

pkgs/data/misc/fedora-backgrounds/generic.nix

@@ -40,11 +40,11 @@ stdenvNoCC.mkDerivation {
     "WP_DIR_LN=$(DESTDIR)/share/backgrounds/$(WP_NAME)"
   ];
 
-  meta = with lib; {
+  meta = {
     homepage = "https://github.com/fedoradesign/backgrounds";
     description = "Set of default and supplemental wallpapers for Fedora";
-    license = licenses.cc-by-sa-40;
-    platforms = platforms.unix;
+    license = lib.licenses.cc-by-sa-40;
+    platforms = lib.platforms.unix;
     maintainers = [ ];
   };
 }

pkgs/data/misc/nixos-artwork/wallpapers.nix

@@ -63,10 +63,10 @@ let
           kdeFilePath = "${pkg}/share/wallpapers/${name}/contents/images/${src.name}";
         };
 
-        meta = with lib; {
+        meta = {
           inherit description license;
           homepage = "https://github.com/NixOS/nixos-artwork";
-          platforms = platforms.all;
+          platforms = lib.platforms.all;
         };
       };
     in