buku: python3 as parameter instead of python

pkgs/applications/misc/buku/default.nix

···
-{ stdenv, pythonPackages, fetchFromGitHub }:
+{ stdenv, python3, fetchFromGitHub }:
 
-with pythonPackages; buildPythonApplication rec {
+with python3.pkgs; buildPythonApplication rec {
   version = "3.0"; # When updating to 3.1, make sure to remove the marked line in preCheck
   name = "buku-${version}";
 

pkgs/top-level/all-packages.nix

···
 
   burp = callPackage ../tools/backup/burp { };
 
-  buku = callPackage ../applications/misc/buku {
-    pythonPackages = python3Packages;
-  };
+  buku = callPackage ../applications/misc/buku { };
 
   byzanz = callPackage ../applications/video/byzanz {};