!per #17799 Remove support for non-permanent deletes

* The permanent flag in deleteMessages
* old records stored with deletion flag are still not
  replayed

akka-docs/rst/java/code/docs/persistence/PersistencePluginDocTest.java

@@ -90,7 +90,7 @@ public class PersistencePluginDocTest {
         }
 
         @Override
-        public Future<Void> doAsyncDeleteMessagesTo(String persistenceId, long toSequenceNr, boolean permanent) {
+        public Future<Void> doAsyncDeleteMessagesTo(String persistenceId, long toSequenceNr) {
             return null;
         }