Some Mob Define Cleanup (#22536)

Just removing a few ancient 2008-era vars that were on every mob
globally, but were completely unused in the modern code. I thought about
removing the Mutations too, but since the Hulk mutation is actually used
by a tiny handful of things, I would probably have to do that in a
separate PR by turning the Hulk code into an Element instead.

code/modules/mob/living/carbon/human/death.dm

@@ -14,7 +14,7 @@
 		I.throw_at(get_edge_target_turf(src,pick(GLOB.alldirs)), rand(1,3), round(30/I.w_class))
 
 	..(species.gibbed_anim)
-	gibs(loc, viruses, dna, null, species.flesh_color, get_blood_color())
+	gibs(loc, dna, null, species.flesh_color, get_blood_color())
 
 /mob/living/carbon/human/dust()
 	vr_disconnect()

code/modules/mob/living/living.dm

@@ -745,10 +745,6 @@ default behaviour is:
 		to_chat(src, SPAN_NOTICE("You can't move..."))
 		return
 	var/resisting = 0
-	for(var/obj/O in requests)
-		requests.Remove(O)
-		qdel(O)
-		resisting++
 	var/resist_power = get_resist_power() // How easily the mob can break out of a grab
 	for(var/obj/item/grab/G in grabbed_by)
 		resisting++

code/modules/mob/living/silicon/death.dm

@@ -1,6 +1,6 @@
 /mob/living/silicon/gib()
 	..("gibbed-r")
-	gibs(loc, viruses, null, /obj/effect/gibspawner/robot)
+	gibs(loc, null, /obj/effect/gibspawner/robot)
 
 /mob/living/silicon/dust()
 	..(/obj/effect/decal/remains/robot)

code/modules/mob/living/simple_animal/friendly/spiderbot.dm

@@ -238,7 +238,7 @@
 		held_item = null
 
 	eject_brain()
-	gibs(loc, viruses, null, /obj/effect/gibspawner/robot) //TODO: use gib() or refactor spiderbots into synthetics.
+	gibs(loc, null, /obj/effect/gibspawner/robot) //TODO: use gib() or refactor spiderbots into synthetics.
 	qdel(src)
 	return