This commit removes Boot's StreamBuilderFactoryBeanCustomizer and
updates KafkaStreamsAnnotationDrivenConfiguration to use
Kafka's StreamsBuilderFactoryBeanConfigurer instead of the
nested class KafkaStreamsFactoryBeanConfigurer.
This aligns more closely with how configuration is typically applied.
See gh-46675
Signed-off-by: Dmytro Nosan <dimanosan@gmail.com>
The enum itself is not specifically tied to auto-configuration so
spring-boot is a better place for it. The related condition,
`@ConditionalOnThreading`, remains in spring-boot-autoconfigure. This
aligns things with the similar `CloudPlatform` and
`@ConditionalOnCloudPlatform`.
Closes gh-46406