I was just wondering when in history the official papal death sentences really ended. I am not interested in any killing that was not officially authorized by a pope (or his authorized representatives) as that would seem more like an potential unsanctioned action (even if done in the name of Catholic faith).
When official papal death sentence end? Never. Because it never started in the first place. Technically such a thing did not exist. Anathema was never officially meant death penalty.
But from your example of Jan Hus, I am assuming your question to be of the executions for holding heretical beliefs. Then the last person to be burned alive at the stake for that was Giordano Bruno, executed February 17, 1600. The last person to die (hanged to death) was Cayetano Ripoll, July 26, 1826.src
BTW the first one was Priscillian (d.385).
That said, I would like to make two points,