create-cluster clean now will clean appendonlydir

In redis#9788, now we stores all persistent append-only files in
a dedicated directory. The name of the directory is determined
by the appenddirname configuration parameter in redis.conf

Update create-cluster clean to clean this default directory.
Fixes redis#10222

utils/create-cluster/create-cluster

@@ -96,9 +96,9 @@ fi
 if [ "$1" == "clean" ]
 then
     rm -rf *.log
-    rm -rf appendonly*.aof
     rm -rf dump*.rdb
     rm -rf nodes*.conf
+    rm -rf appendonlydir
     exit 0
 fi