pyxb EOL notification

[nigelmegitt]

As per pabigot/pyxb#100, pyxb is marked as EOL pending anyone else offering to maintain it, and being accepted as maintainer. This project is completely dependent on pyxb right now, so non-maintenance could be a significant risk.

For an example of a challenge associated with non-maintenance, pabigot/pyxb#123 reveals that pyxb has a problem resulting from a breaking change in Python 3.8, which will also affect this project.

• Is there an alternative we can adopt?

[nigelmegitt]

Quick research suggests some alternatives, without having considered the overall impact of any change:

• xsData (repo) is actively maintained and claims good XML Schema 1.0 and 1.1 support. MIT licence.
• generateDS (repo) is actively maintained and MIT licence, but does not make any particular claim to full conformance or testing against any XML Schema version.
• Just use Python's native ElementTree and write the rest ourselves. Maybe protect against various XML vulnerabilities by using defusedxml

[nigelmegitt]

Successfully switched to renalreg/PyXB-X in the BBC fork, which is also now up to Python3.11 (but doesn't support all functionality yet, for example the autobahn/twisted tests do not pass) - suggest doing the same here.