python3Packages.sphinx: add missing dep packaging

+2
+2
pkgs/development/python-modules/sphinx/default.nix
··· 28 , sphinxcontrib-websupport 29 , typing 30 , setuptools 31 }: 32 33 buildPythonPackage rec { ··· 52 pygments 53 alabaster 54 Babel 55 setuptools 56 snowballstemmer 57 six
··· 28 , sphinxcontrib-websupport 29 , typing 30 , setuptools 31 + , packaging 32 }: 33 34 buildPythonPackage rec { ··· 53 pygments 54 alabaster 55 Babel 56 + packaging 57 setuptools 58 snowballstemmer 59 six