Make auto-configurations final and remove public members #32883
Description
Our auto-configurations are public, but users should reference only the names of these classes. The contained methods, inner classes etc. are not part of the public API (even if they are public by accident or technical reasons).
Make sure that all contained methods and inner classes are not public.
If a @Bean method or inner class is public, deprecate it so that users get a warning that they should not use that method. After some time we will remove the deprecation and drop the public modifier, removing it from public exposed API.
This will leave us with public auto-configuration classes which do not expose any inner classes or methods as public API.