Prior to this commit, a non-singleton FactoryBean was silently replaced
by a singleton bean. In addition, bean definitions for prototype-scoped
and custom-scoped beans were replaced by singleton bean definitions
that were incapable of creating the desired bean instance. For example,
if the bean type of the original bean definition was a concrete class,
an attempt was made to invoke the default constructor which either
succeeded with undesirable results or failed with an exception if the
bean type did not have a default constructor. If the bean type of the
original bean definition was an interface or a FactoryBean that claimed
to create a bean of a certain interface type, an attempt was made to
instantiate the interface which always failed with a
BeanCreationException.
To address the aforementioned issues, this commit reworks the logic in
BeanOverrideBeanFactoryPostProcessor so that an exception is thrown
whenever an attempt is made to override a non-singleton bean.
Closes gh-33602
d79258ac73