matplotlib not installed in setup.py

matplotlib exists in [_deps](https://github.com/patrickvonplaten/controlnet_aux/blob/c8ee2a7e3be86576494a7629cc544bd1790fb179/setup.py#L86) but not in [install_requires](https://github.com/patrickvonplaten/controlnet_aux/blob/c8ee2a7e3be86576494a7629cc544bd1790fb179/setup.py#L167) and extras is empty. Is this intentional? Had to install this by hand in my venv and was kinda surprised 