Allow AIs to greentext survive (#30959)

* Change AI objectives from survive to exist

* Cyberboss simplification

code/game/gamemodes/objective.dm

@@ -348,6 +348,14 @@
 			return FALSE
 	return TRUE
 
+//Like survive, but works for silicons and zombies and such.
+/datum/objective/survive/exist/considered_alive(var/datum/mind/M)
+	if(M && M.current)
+		if(isliving(M.current))
+			var/mob/living/L = M.current
+			return L.stat != DEAD
+	return FALSE
+
 /datum/objective/martyr
 	explanation_text = "Die a glorious death."