Temporary fix for LeaderElect for kube-scheduler

kube-controller-manager defaults --leader-elect to true. We should
do the same for kube-scheduler. kube-scheduler used to have this
set to true, but it got lost during refactoring:

efb2bb71cd

cmd/kube-scheduler/app/server.go

@@ -152,6 +152,9 @@ func NewOptions() (*Options, error) {
 		return nil, err
 	}
 
+	// TODO: we should fix this up better (PR 59732)
+	o.config.LeaderElection.LeaderElect = true
+
 	return o, nil
 }