Add Django 5.2 support to super-csv

[feanil]

Context

Per the Open edX roadmap, this library has been identified as a Django dependency that needs to be updated to support Django 5.2. This update is part of routine platform maintenance and is a prerequisite for upgrading the services that use this library. All Django-dependent libraries must be updated by May 14, 2025, as service upgrades cannot proceed until all library dependencies are compatible.

Required Actions

1. Add Django 5.2 to the test matrix
2. Fix compatibility issues
3. Update documentation
4. Release to PyPI

Resources

• Django 5.2 release notes
• Django Upgrade Guide
• django-upgrade tool - Automatically upgrade your Django code
• Django Upgrade Wiki Page
• For assistance: #wg-maintenance on Slack