For Kotlin libraries, it is a best practice to configure explicitly languageVersion and apiVersion (documented here) to define the minimum version supported and decouple it from the Kotlin version used to compile and test the project.
I would suggest to use a Kotlin 1.9 baseline for Jackson 2.21.x (see spring-projects/spring-boot#49365 related issue), and a Kotlin 2.1 baseline for Jackson 3.x.
For Kotlin libraries, it is a best practice to configure explicitly
languageVersionandapiVersion(documented here) to define the minimum version supported and decouple it from the Kotlin version used to compile and test the project.I would suggest to use a Kotlin 1.9 baseline for Jackson 2.21.x (see spring-projects/spring-boot#49365 related issue), and a Kotlin 2.1 baseline for Jackson 3.x.