Sahra Wagenknecht, a longtime icon of hard-left politics in Germany, is stepping down as co-leader of the populist party she founded only last year. On Monday, Wagenknecht, who started out in politics as a member of East Germany’s communist party, announced that she will not seek reelection as the leader of the party that bears here name — Sahra Wagenknecht Alliance, or BSW. At the same time, she vowed to stay on as a key figure in the party, remaining, in effect, its most prominent leader. “I