More istypes replaced with helpers (#20767)

* shouldn't you be merging these by now

* my oh my do we have a lot of these

* a fellow pedantic shit

code/modules/mob/dead/observer/observer.dm

@@ -345,7 +345,7 @@ This is the proc mobs get to turn into a ghost. Forked from ghostize due to comp
 	set category = "Ghost"
 	set name = "Teleport"
 	set desc= "Teleport to a location"
-	if(!istype(usr, /mob/dead/observer))
+	if(!isobserver(usr))
 		usr << "Not when you're not dead!"
 		return
 	var/A
@@ -417,7 +417,7 @@ This is the proc mobs get to turn into a ghost. Forked from ghostize due to comp
 	set name = "Jump to Mob"
 	set desc = "Teleport to a mob"
 
-	if(istype(usr, /mob/dead/observer)) //Make sure they're an observer!
+	if(isobserver(usr)) //Make sure they're an observer!
 
 
 		var/list/dest = list() //List of possible destinations (mobs)

code/modules/mob/dead/observer/say.dm

@@ -12,7 +12,7 @@
 	if(radio_freq)
 		var/atom/movable/virtualspeaker/V = speaker
 
-		if(istype(V.source, /mob/living/silicon/ai))
+		if(isAI(V.source))
 			var/mob/living/silicon/ai/S = V.source
 			speaker = S.eyeobj
 		else