Update dependency org.jetbrains.kotlin:kotlin-gradle-plugin to v2.4.20-RC

Author: renovate[bot]

gradle/libs.versions.toml

@@ -1,5 +1,5 @@
 [versions]
-kotlin = "2.4.10"
+kotlin = "2.4.20-RC"
 buildconfig = "6.0.10"
 shadow = "9.6.1"
 dokka = "2.2.0"