contrib: add modern `setuptools` and `setuptools_scm` to the packaging venv With `py -3.9 contrib/packaging/packaging.py wix --pyoxidizer-target x86_64-pc-windows-msvc`, there is an immediate failure after building the venv (3.9.13 has `setuptools` 58.1.0): ModuleNotFoundError: No module named 'setuptools.command.build' With that fixed, the same command then fails immediately with this error: Couldn't import setuptools_scm (direct call of setup.py?) Unfortunately, referencing `setuptools` in the requirements file needs `--allow-unsafe` to avoid a warning about not pinning `setuptools`. However, the same warning happens if `setuptools` is pinned to a specific revision, so I have no idea what it is complaining about. It's a separate venv that is only used for packaging, so we can fix it if it becomes a problem in the future. Interestingly, the Inno installer build doesn't fail immediately, and I can see it installing `setuptools` and `setuptools_scm` in the wall of text it emits. Eventually it does fail with the same errors without this change.