Add immunity to ash storm for possessed objects and swords (#23596)

* Add immunity to ash storm for possessed objects

Fixes oversight #23110 by adding immunity to ash storm for possessed objects, addressing the bug where possessed objects, including possessed swords, were not immune to ash storm.

* Make possessed sword immune but not objects

* Code improvment. Both possessed sword and objects now immune

* Ash immunity on children inherited "sword" subtype only

Oopsie

* Fix

---------

Co-authored-by: Pierre-Louis <hernandezpierrelouis@protonmail.com>

code/modules/mob/living/simple_animal/posessed_object.dm

@@ -16,6 +16,7 @@
 
 	no_spin_thrown = TRUE
 	del_on_death = TRUE
+	weather_immunities = list("ash")
 
 	/// The probability % of us escaping if stuffed into a bag/toolbox/etc
 	var/escape_chance = 10

code/modules/mob/living/simple_animal/shade.dm

@@ -62,6 +62,7 @@
 	can_change_intents = FALSE // same here
 	health = 100
 	maxHealth = 100
+	weather_immunities = list("ash")
 
 /mob/living/simple_animal/shade/sword/Initialize(mapload)
 	.=..()