Your heart stops beating when you die now. (tgstation#82305)

## About The Pull Request

Your heart stops beating when you die now.

## Why It's Good For The Game

Did you know spacemen hearts kept beating for like 8 minutes despite
being dead until the organ failure finally stopped it? This is stupid
from a consistency and realism standpoint.

## Changelog
:cl:
balance: Your heart stops beating when you die now.
/:cl:

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

@@ -25,6 +25,7 @@ GLOBAL_LIST_EMPTY(dead_players_during_shift)
 	stop_sound_channel(CHANNEL_HEARTBEAT)
 	var/obj/item/organ/internal/heart/human_heart = get_organ_slot(ORGAN_SLOT_HEART)
 	human_heart?.beat = BEAT_NONE
+	human_heart?.Stop()
 
 	. = ..()