Fix Kotlin example for @ComponentScan basePackages attribute

[maxbiu]

https://docs.spring.io/spring-framework/docs/current/reference/html/core.html#beans-scanning-filters

kotlin to:

@Configuration
@ComponentScan(basePackages = ["org.example"],
        includeFilters = [Filter(type = FilterType.REGEX, pattern = [".*Stub.*Repository"])],
        excludeFilters = [Filter(Repository::class)])
class AppConfig {
    // ...
}