fix: check for partition tree shuffle
fix: check for partition tree shuffle

some maskers, such as text and composite, have a clustering attribute, but attribute is not a numpy ndarray representing a partition tree as partition tree shuffle expects.
this change ensures that if clustering is not the expected numpy ndarray type, it will gracefully fallback to non-partitioned shuffle.

slundberg/shap,slundberg/shap,slundberg/shap,slundberg/shap