metal sheet exploit fix (#6209)

# About the pull request

funny thing I noticed while surfing the code
# Explain why it's good for the game
Im pretty sure thats not how world works
# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl: kivts
fix: Infinite metal oversight fix.
/:cl:

---------

Co-authored-by: Drathek <[email protected]>

code/game/objects/items/frames/table_rack.dm

@@ -100,6 +100,7 @@
 	desc = "A kit for a table, including a large, flat wooden surface and four legs. Some assembly required."
 	icon_state = "wood_tableparts"
 	flags_atom = FPRINT
+	matter = null
 	table_type = /obj/structure/surface/table/woodentable
 
 /obj/item/frame/table/wood/attackby(obj/item/W, mob/user)
@@ -140,6 +141,7 @@
 	desc = "A kit for a table, including a large, flat wooden and carpet surface and four legs. Some assembly required."
 	icon_state = "gamble_tableparts"
 	flags_atom = null
+	matter = null
 	table_type = /obj/structure/surface/table/gamblingtable
 
 /obj/item/frame/table/gambling/attackby(obj/item/W as obj, mob/user as mob)

code/modules/projectiles/gun_attachables.dm

@@ -1761,8 +1761,6 @@ Defined in conflicts.dm of the #defines folder.
 	//but at the same time you are slow when 2 handed
 	aim_speed_mod = CONFIG_GET(number/slowdown_med)
 
-	matter = list("wood" = 2000)
-
 	select_gamemode_skin(type)
 
 /obj/item/attachable/stock/double