Update Kotlin version to 2.1.20

Author: Airsaid

gradle/libs.versions.toml

@@ -11,7 +11,7 @@ alimt = "1.0.3"
 # plugins
 changelog = "2.4.0"
 intelliJPlatform = "2.9.0"
-kotlin = "2.0.21"
+kotlin = "2.1.20"
 kover = "0.9.1"
 qodana = "2025.1.1"
 composePlugin = "1.9.0"