fix: Enforce timetable on proposer check

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

@@ -322,6 +322,7 @@ describe('sequencer', () => {
 
       expect(blockBuilder.buildBlock).not.toHaveBeenCalled();
       expect(publisher.enqueueProposeL2Block).not.toHaveBeenCalled();
+      expect(publisher.canProposeAtNextEthBlock).not.toHaveBeenCalled();
     });
 
     it('does not publish a block if it does not have enough time left in the slot after collecting attestations', async () => {

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

@@ -267,13 +267,13 @@ export class Sequencer extends (EventEmitter as new () => TypedEventEmitter<Sequ
       return;
     }
 
-    this.setState(SequencerState.PROPOSER_CHECK, undefined);
-
     const chainTipArchive = syncedTo.archive;
     const newBlockNumber = syncedTo.blockNumber + 1;
 
     const { slot, ts, now } = this.epochCache.getEpochAndSlotInNextL1Slot();
 
+    this.setState(SequencerState.PROPOSER_CHECK, slot);
+
     // Check that the archiver and dependencies have synced to the previous L1 slot at least
     // TODO(#14766): Archiver reports L1 timestamp based on L1 blocks seen, which means that a missed L1 block will
     // cause the archiver L1 timestamp to fall behind, and cause this sequencer to start processing one L1 slot later.

yarn-project/sequencer-client/src/sequencer/utils.ts

@@ -37,7 +37,8 @@ export type SequencerStateWithSlot =
   | SequencerState.INITIALIZING_PROPOSAL
   | SequencerState.CREATING_BLOCK
   | SequencerState.COLLECTING_ATTESTATIONS
-  | SequencerState.PUBLISHING_BLOCK;
+  | SequencerState.PUBLISHING_BLOCK
+  | SequencerState.PROPOSER_CHECK;
 
 export type SequencerStateCallback = () => SequencerState;