Upgrades

[thmsrmbld]

Django 5.2 Compatibility Update

This PR updates the project to support Django 5.2 while making several other important improvements:

Changes

1. Version bump: Increased package version from 0.3 to 0.4
2. Added support for Django 5.2
3. Deprecated support for Django versions before 4.2
4. Updated classifiers in pyproject.toml accordingly
5. Updated tox configuration to test against Django 4.2, 5.0, 5.2, and main
6. Ensured Django main branch is only tested on Python 3.12
7. Updated GitHub workflow to match the new test matrix

Developer tooling:

1. Updated ruff configuration to use modern syntax structure (moved top-level settings to lint.* sections)
2. Updated ruff command to use modern ruff check syntax
3. Added ruff-format to pre-commit configuration
4. Updated ruff version from v0.1.5 to v0.2.1