33020.Fix - Scikit Learn

The leave-one out errors and model parameters estimated in :class:linear_model.RidgeCV and :class:linear_model.RidgeClassifierCV when cv=None are now numerically stable in the small alpha regime. The default auto option is now equivalent to eigen and picks the cheaper option: eigendecomposition of the covariance matrix when n_features <= n_samples, respectively of the Gram matrix when n_samples > n_features. When store_cv_results=True and X is an integer array, the cv_results_ attribute was wrongly coerced to the integer dtype of X, it now always has a float dtype. By :user:Antoine Baker <antoinebaker>