Consider deprecation and removal of scikit-quant based optimizers

[woodsp-ibm]

The algorithms.optimizers module contains optimizers based on the scikit-quant package - snobfit, imfil and bobyqa. This source code repo for that package seems pretty much unmaintained with last activity 2 years ago and the snobfit issue /scikit-quant/scikit-quant#24, for which unit tests here are skipped, has been open and without any activity since it was created at the end of last year. The Infil optimizer is now emitting numpy deprecation warnings and will break when that function is changed in numpy.

Unlike when these optimizer "wrappers" were added, to conform to the base Optimizer class, there is now also Minimizer protocol so the scikit-quant optimizers could still be used via that e.g. using a partial over their current interface. And as such, given these are breaking down and failing, no longer seem to be supported, and require using older numpy versions to have them work deprecating and removing them from here seems like best course of action but does no longer preclude someone if they really want to use them doing so via the Minimizer protocol that now exists.