Remove the PDPBox package which still relies on sklearn + pin prophet

[Philmod]

#36 274.0   × python setup.py egg_info did not run successfully.
#36 274.0   │ exit code: 1
#36 274.0   ╰─> [18 lines of output]
#36 274.0       The 'sklearn' PyPI package is deprecated, use 'scikit-learn'
#36 274.0       rather than 'sklearn' for pip commands.
#36 274.0       
#36 274.0       Here is how to fix this error in the main use cases:
#36 274.0       - use 'pip install scikit-learn' rather than 'pip install sklearn'
#36 274.0       - replace 'sklearn' by 'scikit-learn' in your pip requirements files
#36 274.0         (requirements.txt, setup.py, setup.cfg, Pipfile, etc ...)
#36 274.0       - if the 'sklearn' package is used by one of your dependencies,
#36 274.0         it would be great if you take some time to track which package uses
#36 274.0         'sklearn' instead of 'scikit-learn' and report it to their issue tracker
#36 274.0       - as a last resort, set the environment variable
#36 274.0         SKLEARN_ALLOW_DEPRECATED_SKLEARN_PACKAGE_INSTALL=True to avoid this error
#36 274.0       
#36 274.0       More information is available at
#36 274.0       https://github.com/scikit-learn/sklearn-pypi-package

I created a bug on their github SauceCat/PDPbox#84