sparse: drop the useless wrapping of `dirstate.set_untracked`
The code of the wrapper only act in the case where the file is not tracked, so this has not effect for `untracked`. In addition the message explicitly mention `add` of a file and no test are breaking if we drop this.
So we drop this for simplicity and cleanup
@echo off
powershell -NoProfile -ExecutionPolicy unrestricted -Command "& '%~dp0\editmergeps.ps1' %*"