The old script did not completely remove the death animation for me, so I modified it. not sure if it's optimal but it does the job for me.
var path = @"C:\data\sprite\몬스터"; // Folder Path
foreach (var actFile in Directory.GetFiles(path, "*.act")) {
var sprFile = actFile.ReplaceExtension(".spr");
var act2 = new Act(actFile, sprFile);
{
act2.AnimationExecute(4, action => {
action.Frames = new List<Frame> { new Frame() };});
}
act2.SaveWithSprite(actFile, sprFile);
}