After migrating to Spring Boot 2.5.0 I get the following warning during startup:

WARN | o.s.h.c.j.Jackson2ObjectMapperBuilder | For Jackson Kotlin classes support please add "com.fasterxml.jackson.module:jackson-module-kotlin" to the classpath

Another person posting this StackOverflow question has this issue as well, but there is no clear/easy solution for it without code changes.
Just like this person I am not using Kotlin at all. Please make it easy to exclude Kotlin from autoconfiguration (as for example like with ThymeLeaf with exclude = {ThymeleafAutoConfiguration.class}, or maybe even solve this automatically for the user entirely.