treewide: clean up 'meta = with' pattern

This commit was created by a combination of scripts and tools:
- an ast-grep script to prefix things in meta with `lib.`,
- a modified nixf-diagnose / nixf combination to remove unused `with lib;`, and
- regular nixfmt.

Co-authored-by: Wolfgang Walther <walther@technowledgy.de>

pkgs/development/python2-modules/enum/default.nix

@@ -19,10 +19,10 @@ buildPythonPackage rec {
 
   doCheck = !isPyPy;
 
-  meta = with lib; {
+  meta = {
     homepage = "https://pypi.python.org/pypi/enum/";
     description = "Robust enumerated type support in Python";
-    license = licenses.gpl2;
+    license = lib.licenses.gpl2;
   };
 
 }