6750e4057c
Related to: https://github.com/spring-projects/spring-kafka/issues/3957 The original commit use a `@Nullable` on some test configuration properties. This branch does not have that import and there is really no reason in `@Nullable` in tests * Remove `@Nullable` from the `ObservationTests` * Fix `try-with-resource` warning in the `MessagingMessageListenerAdapter` * Add explicit `jvmTarget` for Kotlin compiler in the `spring-kafka-docs` module