If a Task is in the 'Completed' I think the only option is to 'Reset' it (see image). You do clear the previous run execution but I think for a repetitive task this is fine.
Maybe this should only be the case if it is in a 'Completed' state rather than 'Failed'. I can see that in this case you would not want to clear the execution because you would want to see why it Failed. Thoughts?