allows janitor keys to be stored in janitor wintercoats and janibets (#78724)

## About The Pull Request
the janitor access key could not be stored on their belt, or their
wintercoat slot, which felt off to me. so i added it to both of them,
and added the janicart key to the coat slot as well. i figure if one can
fit, the other probably can too.
## Why It's Good For The Game
convenient, less cumbersome storage for items that you want to keep both
close to your person, and accessible for easy use.
## Changelog
🆑
qol: allows janitor keys to be stored in janitor wintercoats and
janibets
/🆑

code/game/objects/items/storage/belt.dm

@@ -670,6 +670,7 @@
 	atom_storage.max_slots = 6
 	atom_storage.max_specific_storage = WEIGHT_CLASS_NORMAL // Set to this so the  light replacer can fit.
 	atom_storage.set_holdable(list(
+		/obj/item/access_key,
 		/obj/item/assembly/mousetrap,
 		/obj/item/clothing/gloves,
 		/obj/item/flashlight,

code/modules/clothing/suits/wintercoats.dm

@@ -247,8 +247,10 @@
 	icon_state = "coatjanitor"
 	inhand_icon_state = null
 	allowed = list(
+		/obj/item/access_key,
 		/obj/item/grenade/chem_grenade,
 		/obj/item/holosign_creator,
+		/obj/item/key/janitor,
 		/obj/item/reagent_containers/cup/beaker,
 		/obj/item/reagent_containers/cup/bottle,
 		/obj/item/reagent_containers/cup/tube,