Update to Kotlin 1.4.30

Closes gh-9446

gradle.properties

@@ -3,7 +3,7 @@ gaeVersion=1.9.83
 springJavaformatVersion=0.0.25
 springBootVersion=2.4.0
 version=5.4.3-SNAPSHOT
-kotlinVersion=1.4.20
+kotlinVersion=1.4.30
 org.gradle.jvmargs=-Xmx3g -XX:MaxPermSize=2048m -XX:+HeapDumpOnOutOfMemoryError
 org.gradle.parallel=true
 org.gradle.caching=true