py3-pretend is required to test py3-packaging
If py3-pretend is packaged for Alpine Linux then the full test suite for py3-packaging should pass.
Tests are disabled in py3-packaging-20.3-r0 with
options="!check" and by ignoring specific tests in !8049 (merged)
py3-packaging is a dependency of important python packages including py3-setuptools and py3-pip.