Revert "Update kotlin-gradle-plugin to 1.9.0"

This reverts commit eb7ea6d.

Author: Steve Riesenberg

gradle.properties

@@ -7,7 +7,7 @@ springFrameworkVersion=6.1.0-M4
 micrometerVersion=1.12.0-M2
 openSamlVersion=4.3.0
 version=6.2.0-SNAPSHOT
-kotlinBuildDependencyVersion=1.9.0
+kotlinBuildDependencyVersion=1.8.22
 kotlinDependencyVersion=1.9.0
 samplesBranch=main
 org.gradle.jvmargs=-Xmx3g -XX:+HeapDumpOnOutOfMemoryError