l2geth: verifier sync in parallel with dtl (#2656)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

.changeset/rude-ears-lay.md

+---
+'@eth-optimism/l2geth': patch
+---
+
+Have L2Geth Verifier sync in parallel with the DTL.

l2geth/rollup/sync_service.go

@@ -172,6 +172,7 @@ func NewSyncService(ctx context.Context, cfg Config, txpool *core.TxPool, bc *co
 			}
 		}
 
+		if !cfg.IsVerifier || cfg.Backend == BackendL2 {
 			// Wait until the remote service is done syncing
 			tStatus := time.NewTicker(10 * time.Second)
 			for ; true; <-tStatus.C {
@@ -186,6 +187,7 @@ func NewSyncService(ctx context.Context, cfg Config, txpool *core.TxPool, bc *co
 				}
 				log.Info("Still syncing", "index", status.CurrentTransactionIndex, "tip", status.HighestKnownTransactionIndex)
 			}
+		}
 
 		// Initialize the latest L1 data here to make sure that
 		// it happens before the RPC endpoints open up