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/graphics/eplot/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, gnuplot, ruby }:
+{ lib, stdenv, fetchurl, gnuplot, ruby }:
 
 stdenv.mkDerivation {
   name = "eplot-2.07";
@@ -28,7 +28,7 @@ stdenv.mkDerivation {
     sed -i -e "s|gnuplot -persist|${gnuplot}/bin/gnuplot -persist|" "$out/bin/eplot"
   '';
 
-  meta = with stdenv.lib; {
+  meta = with lib; {
     description = "Create plots quickly with gnuplot";
     longDescription = ''
       eplot ("easy gnuplot") is a ruby script which allows to pipe data easily