PKG: Require python to be old enough for numpy.distutils

https://numpy.org/doc/stable/reference/distutils_status_migration.html
numpy.distutils will never be on Python 3.12, but the build script makes heavy use of it.  Note this requirement in the metadata.

Author: DWesl

setup.py

@@ -96,7 +96,7 @@
               "plotting", "plots", "meteorology", "nwp",
               "numerical weather prediction", "diagnostic",
               "science", "numpy"],
-    python_requires='>=3.7',
+    python_requires='>=3.7, <3.12',
     install_requires=requirements,
     classifiers=["Development Status :: 5 - Production/Stable",
                  "Intended Audience :: Science/Research",