Update Kotlin plugin version and remove mavenLocal repository.

Upgraded the Kotlin multiplatform plugin from version 2.0.21 to 2.1.0 for improved features and compatibility. Removed the mavenLocal repository from the common configuration to streamline dependency resolution.

common.gradle.kts

@@ -3,7 +3,6 @@ version = "0.1.0"
 
 allprojects {
   repositories {
-    mavenLocal()
     mavenCentral()
     maven {
       url = uri("https://gitea.astraeus.nl:8443/api/packages/rnentjes/maven")

settings.common.gradle.kts

@@ -1,6 +1,6 @@
 pluginManagement {
   plugins {
-    kotlin("multiplatform") version "2.0.21"
+    kotlin("multiplatform") version "2.1.0"
   }
   repositories {
     gradlePluginPortal()