Merge pull request #578 from matomo-org/dependabot/gradle/org.jetbrains.kotlin-kotlin-gradle-plugin-2.1.21

Bump org.jetbrains.kotlin:kotlin-gradle-plugin from 2.1.20 to 2.1.21

Author: hannesa2

build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = "2.1.20"
+    ext.kotlin_version = "2.1.21"
     repositories {
         google()
         maven { url "https://plugins.gradle.org/m2/" }