Update kotlin monorepo to v2.4.20

Author: renovate[bot]

gradle/libs.versions.toml

@@ -4,7 +4,7 @@ gradle-api = "8.11.1"
 junit-jupiter = "5.11.4"
 kctfork = "0.13.0"
 kotest = "6.2.4"
-kotlin = "2.4.10"
+kotlin = "2.4.20"
 kotlinx-serialization = "1.11.0"
 lombok = "1.18.48"
 maven-plugin-annotations = "3.16.0"