data-transport-layer: better logging around shutoff block

Adds logging that will make it obvious that the shutoff block
has been reached. Without this logging, it may be possible
to mistake that the shutoff block has been reached because it
has been set.

.changeset/good-clocks-relax.md

+---
+'@eth-optimism/data-transport-layer': patch
+---
+
+Add better logging to DTL about shutoff block

packages/data-transport-layer/src/services/l1-ingestion/service.ts

@@ -277,6 +277,12 @@ export class L1IngestionService extends BaseService<L1IngestionServiceOptions> {
             depositTargetL1Block,
             handleEventsTransactionEnqueued
           )
+        } else {
+          this.logger.info('Deposit shutoff reached', {
+            depositTargetL1Block,
+            highestSyncedL1Block,
+            depositShutoffBlock,
+          })
         }
 
         await this._syncEvents(