`dond` error in finally block

[einsmein]

finally block in dond (here) relies on a parameter from try block. This results in an UnboundLocalError when the exception happens before datasavers is assigned.

    try:
        with _catch_interrupts() as interrupted, ExitStack() as stack, params_meas_caller as call_params_meas:
            datasavers = [
                stack.enter_context(group.measurement_cxt.run())
                for group in measurements.groups
            ]
        ...
    finally:
        for datasaver in datasavers:
            ...