PR 12701 makes breaking changes in the inspect module.

Currently we have two sets of APIs in the inspect module: old deprecated API that do not support keyword-only arguments, and new *full* API that supports them. Even many years since 3.0 the old API still has not been removed. Adding support for positional-only arguments needs changes of the same order as adding support of keyword-only arguments. It means deprecating the current API and introducing a new (*fuller*?) API. This is a slow process for many releases. We could also take opportunity to redesign APIs completely instead of just adding new parameters and fields.

I suggest to remove all breaking changes in the inspect module and defer them to the separate issue. This perhaps will need a discussion on Python-Dev, and maybe not one.