Use the bean factory to get the type produced by a factory bean

Previously, we only looked at the OBJECT_TYPE_ATTRIBUTE on the
factory bean's definition. This did not work for situations
where the information's provided by the definition's target type
rather than the attribute.

Rather than manually considering the target type in addition to
the existing consideration of the attribute, we now ask the bean
factory for the type that will be produced by the factory bean
instead. This should insulate us from any changes and
enhancements in Framework in the future.

Fixes gh-40234

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockitoPostProcessor.java

@@ -254,9 +254,8 @@ public class MockitoPostProcessor implements InstantiationAwareBeanPostProcessor
 		Class<?> type = resolvableType.resolve(Object.class);
 		for (String beanName : beanFactory.getBeanNamesForType(FactoryBean.class, true, false)) {
 			beanName = BeanFactoryUtils.transformedBeanName(beanName);
-			BeanDefinition beanDefinition = beanFactory.getBeanDefinition(beanName);
-			Object attribute = beanDefinition.getAttribute(FactoryBean.OBJECT_TYPE_ATTRIBUTE);
-			if (resolvableType.equals(attribute) || type.equals(attribute)) {
+			Class<?> producedType = beanFactory.getType(beanName, false);
+			if (type.equals(producedType)) {
 				beans.add(beanName);
 			}
 		}