Update kotlin monorepo to v2.1.20

Author: renovate[bot]

junit5-jupiter-starter-maven-kotlin/pom.xml

@@ -10,7 +10,7 @@
 
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<kotlin.version>2.1.10</kotlin.version>
+		<kotlin.version>2.1.20</kotlin.version>
 		<maven.compiler.source>1.8</maven.compiler.source>
 		<maven.compiler.target>${maven.compiler.source}</maven.compiler.target>
 	</properties>