Revert "Release 6.0.0-RC1"

This reverts commit 334adaef378b86a694fdd646a2d8a867a5765147.

gradle.properties

@@ -5,7 +5,7 @@ springBootVersion=2.4.2
 springFrameworkVersion=6.0.0-RC1
 micrometerVersion=1.10.0-RC1
 openSamlVersion=4.1.1
-version=6.0.0-RC1
+version=6.0.0-SNAPSHOT
 kotlinVersion=1.7.20
 samplesBranch=main
 org.gradle.jvmargs=-Xmx3g -XX:+HeapDumpOnOutOfMemoryError