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/misc/unclutter/default.nix

@@ -1,4 +1,4 @@
-{stdenv, fetchurl, xlibsWrapper}:
+{lib, stdenv, fetchurl, xlibsWrapper}:
 
 stdenv.mkDerivation {
   name = "unclutter-8";
@@ -18,7 +18,7 @@ stdenv.mkDerivation {
     make DESTDIR="$out" MANPATH="$out/share/man" PREFIX="" install.man
   '';
 
-  meta = with stdenv.lib; {
+  meta = with lib; {
     description = "Hides mouse pointer while not in use";
     longDescription = ''
       Unclutter hides your X mouse cursor when you do not need it, to prevent