We create Python packages at https://github.com/sagemath/database_stein_watkins
that serve as the new upstream.

The actual files will be accessed via importlib.resources; actually the backport package importlib-resources, because Python 3.8 does not have files and as_file. Also we need the added support for package resources in namespace packages: the distributions database-stein-watkins-mini and database-stein-watkins-huge both share the namespace database_stein_watkins.

Currently database-stein-watkins-huge is only a placeholder. Whether we can publish the huge package to PyPI will depend on whether the size limit request at pypi/support#1946 is successful.

We use hatchling as the build system. It supports PEP 660 editable wheels and namespace packages. (flit_core is not suitable - it does not have support for resources in namespace packages.)

Part of Meta-ticket #30914: Create upstream repositories, pip-installable packages for database packages

CC: @williamstein

Component: packages: optional

Author: Matthias Koeppe

Branch/Commit: u/mkoeppe/new_upstream_for_database_stein_watkins @ fb43593

Issue created by migration from https://trac.sagemath.org/ticket/33881