[scikit-learn] Deprecation of the 'sklearn' PyPI package starts December 1st

[Loïc Estève]

Hi everyone,

"pip install scikit-learn" has always been the supported way to install
scikit-learn with pip, but for some time, "pip install sklearn" has been
working too.

The scikit-learn team has decided to gradually deprecate the 'sklearn'
PyPI package by doing a brownout over one year:
- starting December 1st 2022, using 'sklearn' rather than 'scikit-learn'
  for pip commands will start to raise an error over some predefined
  time windows
- these time windows durations will gradually increase over one year
- on December 1st 2023, using 'sklearn' rather than 'scikit-learn' for
  pip commands will always raise an error

More information about the 'sklearn' package deprecation is available at
https://github.com/scikit-learn/sklearn-pypi-package.

Any concerns about this, let us know by replying to this email or by
creating an issue at
https://github.com/scikit-learn/sklearn-pypi-package/issues/new.

Cheers,
Loïc