Add setuptools to install_requires (#2720)

When installing a pre-built wheel in a venv on Python 3.12, calling
`nrniv` fails because the wrapper script uses `setuptools` for some
functionality, so it should also be added as a runtime dependency.

setup.py

@@ -509,7 +509,7 @@ def setup_package():
             else "node-and-date"
         },
         cmdclass=dict(build_ext=CMakeAugmentedBuilder, docs=Docs),
-        install_requires=["numpy>=1.9.3", "packaging", "find_libpython"],
+        install_requires=["numpy>=1.9.3", "packaging", "find_libpython", "setuptools"],
         tests_require=["flake8", "pytest"],
         setup_requires=["wheel", "setuptools_scm"]
         + maybe_docs