Update kotlin

build.gradle.kts

@@ -2,7 +2,7 @@ plugins {
     id("com.gradleup.shadow") version "8.3.2" // Import shadow API.
     java // Tell gradle this is a java project.
     eclipse // Import eclipse plugin for IDE integration.
-    kotlin("jvm") version "2.0.20" // Import kotlin jvm plugin for kotlin/java integration.
+    kotlin("jvm") version "2.0.21" // Import kotlin jvm plugin for kotlin/java integration.
 }
 
 java {