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/desktops/xfce/panel-plugins/xfce4-datetime-plugin/default.nix

@@ -1,5 +1,5 @@
 { mkXfceDerivation
-, stdenv
+, lib, stdenv
 , intltool
 , libxfce4ui
 , xfce4-panel
@@ -26,7 +26,7 @@ mkXfceDerivation {
     xfce4-panel
   ];
 
-  meta = with stdenv.lib; {
+  meta = with lib; {
     description = "Shows the date and time in the panel, and a calendar appears when you left-click on it";
     maintainers = [ maintainers.AndersonTorres ];
   };