[FIX] Cult Shadow Shackles can now cuff people who are missing an arm. (#26707)

* Copies the requirements from handcuff code

* This proc is never implemented

* Removes unused procs

code/modules/surgery/organs/organ_helpers.dm

@@ -74,24 +74,6 @@
 		return TRUE
 	return FALSE
 
-//Limb numbers
-/mob/proc/get_num_arms()
-	return 2
-
-/mob/living/carbon/human/get_num_arms()
-	. = 0
-	for(var/X in bodyparts)
-		var/obj/item/organ/external/affecting = X
-		if(affecting.body_part == ARM_RIGHT)
-			.++
-		if(affecting.body_part == ARM_LEFT)
-			.++
-
-//sometimes we want to ignore that we don't have the required amount of arms.
-/mob/proc/get_arm_ignore()
-	return FALSE
-
-
 /mob/proc/get_num_legs()
 	return 2