fixes arm implants breaking the drop key (tgstation#65002)

fixes tgstation#65001 (Surgical Toolset Implants (possibly integrated toolset implants too?) cause the drop hotkey to stop working properly)

The dropkey signal always gets called, even when the item isnt extended.
Comsig_kb_activated cancels the key from being sent

We were doing our check inside retract, but we always assumed the dropped item was us. bad

code/modules/mining/lavaland/tendril_loot.dm

@@ -828,7 +828,7 @@
 /obj/item/organ/cyberimp/arm/katana/Retract()
 	var/obj/item/cursed_katana/katana = active_item
 	if(!katana || katana.shattered)
-		return
+		return FALSE
 	if(!katana.drew_blood)
 		to_chat(owner, span_userdanger("[katana] lashes out at you in hunger!"))
 		playsound(owner, 'sound/magic/demon_attack1.ogg', 50, TRUE)

code/modules/surgery/organs/augments_arms.dm

@@ -114,12 +114,12 @@
 		return //How did we even get here
 	if(hand != host.hand_bodyparts[host.active_hand_index])
 		return //wrong hand
-	Retract()
-	return COMSIG_KB_ACTIVATED
+	if(Retract())
+		return COMSIG_KB_ACTIVATED
 
 /obj/item/organ/cyberimp/arm/proc/Retract()
 	if(!active_item || (active_item in src))
-		return
+		return FALSE
 
 	owner?.visible_message(span_notice("[owner] retracts [active_item] back into [owner.p_their()] [zone == BODY_ZONE_R_ARM ? "right" : "left"] arm."),
 		span_notice("[active_item] snaps back into your [zone == BODY_ZONE_R_ARM ? "right" : "left"] arm."),
@@ -128,6 +128,7 @@
 	owner.transferItemToLoc(active_item, src, TRUE)
 	active_item = null
 	playsound(get_turf(owner), retract_sound, 50, TRUE)
+	return TRUE
 
 /obj/item/organ/cyberimp/arm/proc/Extend(obj/item/augment)
 	if(!(augment in src))