treewide: with stdenv.lib; in meta -> with lib;

Part of: https://github.com/NixOS/nixpkgs/issues/108938

meta = with stdenv.lib;

is a widely used pattern. We want to slowly remove
the `stdenv.lib` indirection and encourage people
to use `lib` directly. Thus let’s start with the meta
field.

This used a rewriting script to mostly automatically
replace all occurances of this pattern, and add the
`lib` argument to the package header if it doesn’t
exist yet.

The script in its current form is available at
https://cs.tvl.fyi/depot@2f807d7f141068d2d60676a89213eaa5353ca6e0/-/blob/users/Profpatsch/nixpkgs-rewriter/default.nix

pkgs/tools/text/diffutils/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, xz, coreutils ? null }:
+{ lib, stdenv, fetchurl, xz, coreutils ? null }:
 
 # Note: this package is used for bootstrapping fetchurl, and thus
 # cannot use fetchpatch! All mutable patches (generated by GitHub or
@@ -25,7 +25,7 @@ stdenv.mkDerivation rec {
     stdenv.lib.optional (coreutils != null) "PR_PROGRAM=${coreutils}/bin/pr"
     ++ stdenv.lib.optional (stdenv.buildPlatform != stdenv.hostPlatform) "gl_cv_func_getopt_gnu=yes";
 
-  meta = with stdenv.lib; {
+  meta = with lib; {
     homepage = "https://www.gnu.org/software/diffutils/diffutils.html";
     description = "Commands for showing the differences between files (diff, cmp, etc.)";
     license = licenses.gpl3;