gh-40471: Remove the experimental "surf" package
    
and the one method that tries to use it. This has been broken since
2009:

* #6316
* #22590

I suppose it's possible that someone is passing `algorithm="surf"` to
this method and then ignoring the fact that it doesn't work, but I'm
hoping we can pretend they're not in order to get this done without a
one-year deprecation period for something that hasn't worked since the
iPhone 1.

The only tests that are affected are the `# optional - surf` ones. The
others are in fact testing the `MPolynomialIdeal.plot()` method, which
has its own, identical, tests. Note also that the docs for
`MPolynomialIdeal.plot()` specify **two** variables, so deleting the
three-variable case (which doesn't work!) does not break any promises.
    
URL: #40471
Reported by: Michael Orlitzky
Reviewer(s): Tobias Diez

Author: Release Manager