do cron each 1/4th of epoch

[Marketen]

We execute performance cron each 1/4 of epoch duration. Also simplified trackValidatorsPerformanceCron

• Store in a variable outside the cron the lastProcessedEpoch so we dont retry once an epoch has been processed
• Get rid of helper trackValidatorsPerformance. Everything is done inside trackValidatorsPerformanceCron.
• Use finallyafter try-catch block of trackValidatorsPerformanceCron to write to db the data (everything went well) or the error (sometthing happened)

[pablomendezroyo]

Why not moving

let lastProcessedEpoch: number | undefined = undefined;

to the file trackValidatorsPerformanceCron and do there the logic of

    const currentEpoch = await beaconchainApi.getEpochHeader({ blockId: "finalized" });

    if (currentEpoch !== lastProcessedEpoch) {
      await trackValidatorsPerformanceCron({
        brainDb,
        postgresClient,
        beaconchainApi,
        executionClient,
        consensusClient,
        currentEpoch
      });
      lastProcessedEpoch = currentEpoch;
    }
  } catch (error) {
    logger.error(`Failed to fetch or process epoch:`, error);
  }

This way the index.ts would look cleaner. You can wrap this logic in a new function and call just this function in the cron

[Marketen]

done