Remove WithKeywordsWhenNeeded

[JonRowe]

My approach to try to split args and use **kwargs for delegation is incorrect and needs to be phased out in 3.x and this module removed in 4.x. The problem is that arguments that implement to_hash are wrongly detected (with no way to know they are not) and converted. Only ruby2_keywords delegation is safe.

See rspec/rspec-expectations#1241 as an example of this issue.

[pirj]

A WIP attempt to get rid of WKWN in rspec-core rspec/rspec-core@684b584

I've been running it on Ruby 3.0, and the spec fails with something like foo: keyword missing for those lines where we pass a hash:

include_examples "...", { foo: "..." }