Running the tests clears the user's login token #1632

1. Run the system test services
2. Login - uv run blueapi login
3. Check login works - uv run blueapi controller devices
4. Run tests - `uv run pytest tests/unit
5. See that you've been logged out - uv run blueapi controller devices - gives auth error

This is a pain even if it's not really a bug in blueapi itself.