[3.12] gh-105084: Tests: Use setuptools+wheel from sysconfig.get_config_var('WHEEL_PKG_DIR') if set (#105056) (#105424)

Includes part of the changes from afa759fb800be416f69e3e9c9b3efe68006316f5,
to make this apply.

Co-Authored-By: Lysandros Nikolaou <lisandrosnik@gmail.com>

(cherry picked from commit bd98b65e974b7a1e086a51e7b55131582f7a0491)