Updates for new scikit-learn and python 3.11

[kodai2199]

Hi, I was trying to run lemon using Python 3.11.2 and scikit-learn 1.5.2. I ran into some issues due to API changes. Namely, in the OneHotEncoder of scikit-learn the "sparse" keyword argument was renamed to "sparse_output" in 1.2, while in Python 3.11 the Random object now requires very specific types, so I had to cast np.int64 to int().