Release 5.8.15

gradle.properties

@@ -1,5 +1,5 @@
 springBootVersion=2.7.12
-version=5.8.15-SNAPSHOT
+version=5.8.15
 samplesBranch=5.8.x
 org.gradle.jvmargs=-Xmx3g -XX:MaxPermSize=2048m -XX:+HeapDumpOnOutOfMemoryError
 org.gradle.parallel=true