The Python licenses include the fairly permissive BDB License, stating the following:

• Redistributions in any form must be accompanied by information on how to obtain complete source code for the DB software and any accompanying software that uses the DB software.

This would mean that either the Python distributions cannot be redistributed with e.g, commercial software, or is this license not applicable for the final "install-only" builds i.e., which would require the Berkley DB to be installed separately?

See also the link from the official Python 3 docs, where it mentions that Berkley DB hasn't been included since Python 2 (Python "bindings" for Oracle Berkeley DB.