Update Python & Django supported versions + migrate to ruff

[samiashi]

• Drop support for Python 3.7 and 3.8
• Drop support for Django < 4.2
• Add support for Python 3.9, 3.11, 3.12 and 3.13
• Add support for Django 5.0, 5.1 and 5.2

This PR also fixes a bug when using Django Admin Shell with dynamic models (models created at runtime), you might encounter the following error:

AttributeError: module 'your_app.models' has no attribute 'your_dynamic_model_name'

This happens because Django Admin Shell attempts to import all models registered with Django's app registry, but dynamic models might not be directly accessible as attributes of their declared module.

[djk2]

Hi. Sorry for very very long time without any response. I will review this PR in this week. Looks very nice. Thank You