[edx_credentials_themes]: Add Support for Django 4.2

[github-actions]

Description

Follow and Complete all of the following steps for the issue to be marked as done.

• Update tox & Github action workflow using modernisers to add support for Django 4.2
• Remove any versions of Python earlier than 3.8 from tox.ini, .travis.yml, and GitHub Actions workflows.
• Update the trove classifiers in setup.py, setup.cfg or pyproject.toml files.
• Run and verify all tests are passing in the CI for Django 4.2
• Run available code-mods to fix the failing tests
• Add CHANGELOG entry with description “Support added for Django 4.2”
• Bump the package version and release a new version on GitHub & PyPI (whichever is applicable)
• Update the repo support field in the Dependency Upgrade Sheet.

[UsamaSadiq]

Hi @justinhynes upon reviewing the changes made for Django 4.2 support in the credentials-themes repo, I realized this repo doesn't have any Django related functionality (except translations perhaps) at all so I believe it would be more appropriate to remove the Django dependency and related targets from the repository.
What would be your opinion on it?