NR UE: don't activate HARQ process for PUCCH transmission if feedback is disabled

Currently we still activated the DL HARQ process for PUCCH transmission,
and only at the time of the scheduled PUCCH transmission, we actually skip sending the ACK.
This is not only unnecessary, it is at least misleading and strange that
DL HARQ processes can be reused in the meantime, even though they are active...

Therefore simply don't activate the DL HARQ process by skipping the call to set_harq_status() if feedback for it is disabled.

openair2/NR_UE_PHY_INTERFACE/NR_IF_Module.c

@@ -1190,7 +1190,7 @@ void update_harq_status(NR_UE_MAC_INST_t *mac, uint8_t harq_pid, uint8_t ack_nac
       current_harq->ack_received = true;
     }
   }
-  else {
+  else if (!get_FeedbackDisabled(mac->sc_info.downlinkHARQ_FeedbackDisabled_r17, harq_pid)) {
     //shouldn't get here
     LOG_E(NR_MAC, "Trying to process acknack for an inactive harq process (%d)\n", harq_pid);
   }