the current version is buggy, as we found out on #27870

also, pkgconfig switched to https://python-poetry.org/ from setuptools, so we either get poetry installed too (which is a big task), or go Debian way and provide setup.py. That's what they do in their (not really "orig") tarball on

http://deb.debian.org/debian/pool/main/p/python-pkgconfig/

Cf. https://salsa.debian.org/python-team/modules/python-pkgconfig/tree/master

The pypi tarball has setup.py, so we can just use it.
tarball: https://files.pythonhosted.org/packages/6e/a9/ff67ef67217dfdf2aca847685fe789f82b931a6957a3deac861297585db6/pkgconfig-1.5.1.tar.gz

CC: @kiwifb @embray @tobihan @infinity0 @isuruf @mkoeppe

Component: packages: standard

Author: Dima Pasechnik

Branch: fb8f4e5

Reviewer: Isuru Fernando, Erik Bray, Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/28883