> Of course we, like all other python projects, don't support using other dependency versions then the ones in the requirements.txt file. So when someone just uses a different minor version of django, stuff breaks

That sounds wrong. A Python package should not have a requirements.txt file at all. A requirements.txt file is for "freezing" and fully reproducing an environment (ie. in a virtualenv or docker container). This is useful for certain applications like deploying services or sharing notebooks etc. It is not for packages. A package should document its requirements via setup.py/pyproject.toml and do so in the loosest way possible. Django uses semver and Django apps don't generally need to pin to minor versions.

Stuff like this is why people think Python packaging is worse than it really is.