Seed for XGBoost for Random Forest in section 8.3

[fizban99]

It seems that using the seed 42 with xgboost 1.7.6 with the sample data used in section 8.3 returns a score of 0.7535911602209945 which is different from the value on the book. Actually, using the value 39 for the seed replicates the value of the book of 0.7447513812154696 The default hyperparameters are mostly set to None in 1.7.6, but that does not seem to affect the score.