New XGBoost model needed

[mdeceglie]

A new warning from XGBoost has bubbled up in our notebook checks.

WARNING: /var/folders/sy/f16zz6x50xz3113nwtb9bvq00000gp/T/abs_b2k4a2hea3/croot/xgboost-split_1675457783214/work/src/learner.cc:888: Found JSON model saved before XGBoost 1.6, please save the model using current version again. The support for old JSON model will be discontinued in XGBoost 2.3.

The version of xgboost used in that test environment should be 1.5.1, how that knows to complain about something related to 1.6... ¯_(ツ)_/¯