refactor: Move pascals triange to maths/ (#7932)

* refactor: Move pascals triange to maths/

* Update xgboost_classifier.py

* statsmodels is now compatible with Python 3.11

* statsmodels is now compatible with Python 3.11

* cython>=0.29.28

* cython>=0.29.28  # For statsmodels on Python 3.11

Co-authored-by: Christian Clauss <cclauss@me.com>