Handling of already canonical payloads (#4367)

* deprecated ACCEPTED status

* pre-check for existing canonical header

eth/stagedsync/stage_headers.go

@@ -418,6 +418,22 @@ func handleNewPayload(
 		return err
 	}
 
+	isCanonicalHeader, err := rawdb.IsCanonicalHash(tx, headerHash)
+	if err != nil {
+		return err
+	}
+
+	// If we already processed this block as canonical we return VALID and skip it.
+	if isCanonicalHeader {
+		if requestStatus == engineapi.New {
+			cfg.hd.PayloadStatusCh <- privateapi.PayloadStatus{
+				Status:          remote.EngineStatus_VALID,
+				LatestValidHash: rawdb.ReadHeadBlockHash(tx),
+			}
+		}
+		return nil
+	}
+
 	if existingCanonicalHash != (common.Hash{}) && headerHash == existingCanonicalHash {
 		log.Info(fmt.Sprintf("[%s] New payload: previously received valid header", s.LogPrefix()))
 		cfg.hd.BeaconRequestList.Remove(requestId)