The Python 3 variant do not need these.
* gnu/packages/python-compression.scm (python-zipp)[native-inputs]: Remove
PYTHON-CONTEXTLIB2, PYTHON-PATHLIB2, and PYTHON-UNITTEST2.
[properties]: New field.
(python2-zipp)[native-inputs]: Add PYTHON2-CONTEXTLIB2, PYTHON2-PATHLIB2, and
PYTHON2-UNITTEST2.