Test suite failing due to deprecated --rsyncdir

pytest-xdist 3.0.2 [deprecated support for --rsyncdir](https://github.com/pytest-dev/pytest-xdist/blob/master/CHANGELOG.rst#pytest-xdist-302-2022-10-25). As a result, Setuptools test suite now fails early with an INTERNALERROR when that deprecation warning is hit while `-W error` is indicated ([example](https://github.com/pypa/setuptools/actions/runs/3336662802/jobs/5522084728)).