test(fast-inbox): drop isOpen from the sequencer inbox bucket fixtures (A-1382)

Author: spalladino

yarn-project/sequencer-client/src/sequencer/checkpoint_proposal_job.test.ts

@@ -1416,7 +1416,6 @@ describe('CheckpointProposalJob', () => {
         timestamp: 0n,
         msgCount: 2,
         lastMessageIndex: 4n,
-        isOpen: false,
       };
       const bundle = Array.from({ length: 5 }, (_, i) => new Fr(i + 1));
       l1ToL2MessageSource.getLatestInboxBucketAtOrBefore.mockResolvedValue(bucket);

yarn-project/sequencer-client/src/sequencer/inbox_bucket_selector.test.ts

@@ -30,7 +30,6 @@ function makeSource(specs: TestBucketSpec[]): {
       timestamp: spec.timestamp,
       msgCount: spec.msgCount,
       lastMessageIndex: total - 1n,
-      isOpen: false,
     });
   }