treewide: remove unused with statements from maintainer lists

$ find -type f -name '*.nix' -print0 | xargs -P "$(nproc)" -0 sed -i \
  -e 's!with lib.maintainers; \[ *\];![ ];!' \
  -e 's!with maintainers; \[ *\];![ ];!'

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

@@ -29,6 +29,6 @@ buildPythonPackage rec {
     description = "Plugin and hook calling mechanisms for Python";
     homepage = "https://github.com/pytest-dev/pluggy";
     license = lib.licenses.mit;
-    maintainers = with lib.maintainers; [ ];
+    maintainers = [ ];
   };
 }