Explicitly support Python 3.12
What's Changed
* GitHub Actions: Add Python 3.12 to the testing by cclauss in https://github.com/SvenskaSpel/har2locust/pull/5
* GitHub Actions: Simplify the code to leverage 'tox -e py' by cclauss in https://github.com/SvenskaSpel/har2locust/pull/6
New Contributors
* cclauss made their first contribution in https://github.com/SvenskaSpel/har2locust/pull/5
**Full Changelog**: https://github.com/SvenskaSpel/har2locust/compare/0.8.4...0.8.5