hotfix(operator): assign SubscribeToNewTasksV3() correctly

[JuArce]

Assign SubscribeToNewTasksV3() correctly

Description

In operator/pkg/operator.go the SubscribeToNewTasksV3() is being assigned to subV2

		case err := <-subV3:
			o.Logger.Infof("Error in websocket subscription", "err", err)
			subV2, err = o.SubscribeToNewTasksV3()
			if err != nil {
				o.Logger.Fatal("Could not subscribe to new tasks V3")
			}

Type of change

• Bug fix

Checklist

• “Hotfix” to testnet, everything else to staging
• Linked to Github Issue
• This change depends on code or research by an external entity
  • Acknowledgements were updated to give credit
• Unit tests added
• This change requires new documentation.
  • Documentation has been added/updated.
• This change is an Optimization
  • Benchmarks added/run
• Has a known issue
  • Link to the open issue addressing it
• If your PR changes the Operator compatibility (Ex: Upgrade prover versions)
  • This PR adds compatibility for operator for both versions and do not change batcher/docs/examples
  • This PR updates batcher and docs/examples to the newer version. This requires the operator are already updated to be compatible