Update kotlin monorepo to v2.3.20

Author: renovate[bot]

gradle/libs.versions.toml

@@ -12,7 +12,7 @@ kotest = "5.9.1"
 kotlinxCoroutines = "1.10.2"
 kotestArrow = "2.0.0"
 # @pin
-kotlin = "2.2.21"
+kotlin = "2.3.20"
 kotlinBinaryCompatibilityPlugin = "0.18.1"
 kotlinLogging = "7.0.14"
 mavenPublish = "0.35.0"