Revert ":arrow_up: Bump org.jetbrains.kotlin.jvm from 2.1.20 to 2.1.21 (#132)"

This reverts commit 6e3e4fb.

Author: patou

gradle/libs.versions.toml

@@ -6,7 +6,7 @@ opentest4j = "1.3.0"
 # plugins
 changelog = "2.2.1"
 intelliJPlatform = "2.5.0"
-kotlin = "2.1.21"
+kotlin = "2.1.20"
 kover = "0.9.1"
 qodana = "2024.3.4"