* ``sitepackages = true`` will add user's site-package to the python path on Windows as expected
* Avoid importing ``pipes`` on Python 3.3+ to avoid ``DeprecationWarning`` on Python 3.11
* Fix ``isolated_build`` when the build process produces stderr at exit.
* Fixed failing isolated_build because setuptools warning was captured
in ``build_requires``.
* Avoid potential 30s delay caused by socket.getfqdn().
* Ignore missing commands if they are prefixed by ``-``
OBS-URL: https://build.opensuse.org/package/show/devel:languages:python/python-tox?expand=0&rev=86