#17644 introduced code in Tree.__setstate__ to deal with pickles saved in a different endianness that the endianness on the machine the pickle is loaded on.

#21237 showed that this fix was not working since there is an error in Tree.__cinit__ (i.e .before __setstate__). This is probably better to remove this tricky code if it is not useful.

Side-comment: this problem is avoided with joblib 1.1 which loads arrays in native endianness (same behaviour as pickle).

While I am at it adding a test with a pickle generated on a big-endian machine would be nice.