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/development/python-modules/hyperopt/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchPypi, buildPythonPackage
+{ lib, stdenv, fetchPypi, buildPythonPackage
 , cloudpickle, numpy, future, networkx
 , six, tqdm, scipy, pymongo
 }:
@@ -19,7 +19,7 @@ buildPythonPackage rec {
 
   pythonImportsCheck = [ "hyperopt" ];
 
-  meta = with stdenv.lib; {
+  meta = with lib; {
     description = "Distributed Asynchronous Hyperparameter Optimization";
     homepage    = "http://hyperopt.github.com/hyperopt/";
     license     = licenses.bsd2;