This patchset adds the Optuna hyperparameter optimization framework.
Optuna requires a number of ML frameworks for the whole test suite. I deleted some test files and added comments on missing packages.
I packaged Skorch in the series but it's an optional dependency that is only used in the integration tests, which are completely disabled. The latest version of scikit-optimize (0.8.1), another optional dependency, is incompatible with the scikit-learn version in Guix (0.24.x). I am waiting for the next release to package it. The other dependencies are trickier.
The executable in bin/ throws an error coming from pygobject, which I couldn't update. While there is a CLI, Optuna is mainly used as a library, that is why I prefix it with python-.