skorch models raising The SHAP explanations do not sum up to the model's output

[Oege Dijk]

Seems related to this bug: shap/shap#3363

Can be avoided with passing shap_kwargs=dict(check_additivity=False) to the explainer, but then you might get inaccurate shap values.

Added check_additivity=False param to the skorch tests for now.