chore: Downgrade Kotlin to 1.6 for backward compatibility (#32)

* chore - Downgrade Kotlin to 1.6 for backward compatibility

Author: lorenzsimon

pom.xml

@@ -47,7 +47,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <kotlin.version>1.7.10</kotlin.version>
+        <kotlin.version>1.6.21</kotlin.version>
     </properties>
 
     <build>