XAUTOCLAIM: JUSTID should prevent incrementing delivery_count (#8724)

To align with XCLAIM and the XAUTOCLAIM docs

src/t_stream.c

@@ -3121,6 +3121,8 @@ void xautoclaimCommand(client *c) {
 
         /* Update the consumer and idle time. */
         nack->delivery_time = now;
+        /* Increment the delivery attempts counter unless JUSTID option provided */
+        if (!justid)
             nack->delivery_count++;
 
         if (nack->consumer != consumer) {