fix: update jdk

Author: Angular2Guy

source-sink/pom.xml

@@ -38,7 +38,7 @@
 	</scm>
 	<properties>
 		<jaxb-maven-plugin.version>4.0.8</jaxb-maven-plugin.version>
-		<java.version>25</java.version>
+		<java.version>21</java.version>
 		<kotlin.version>1.9.25</kotlin.version>
 	</properties>
 	<dependencies>