Bump kotlin from 2.0.20->2.0.21

Feilet å bumpe til 2.1.0

Author: hestad

gradle/libs.versions.toml

@@ -6,7 +6,7 @@ slf4j = "2.0.16"
 kittinunf = "2.3.1"
 wiremock = "3.9.1"
 jupiter = "5.11.3"
-kotlin = "2.0.20"
+kotlin = "2.0.21"
 ktor = "2.3.12"
 arrow = "1.2.4"
 jackson = "2.17.2"