Storage z-fighting bugfix (#20518)

Fixes this shit from happening.

<img width="256" alt="dreamseeker_siriznpX2I"
src="https://github.com/user-attachments/assets/ed7c1daa-79bb-4030-9667-547d7756d350"
/>

code/modules/psionics/equipment/psipower.dm

@@ -8,6 +8,7 @@
 	throw_speed = 0
 	var/maintain_cost = 3
 	var/mob/living/owner
+	w_class = WEIGHT_CLASS_NO_CONTAINER
 
 /obj/item/psychic_power/New(var/mob/living/_owner)
 	owner = _owner
@@ -24,9 +25,6 @@
 	STOP_PROCESSING(SSprocessing, src)
 	. = ..()
 
-/obj/item/psychic_power/get_storage_cost()
-	return 5
-
 /obj/item/psychic_power/attack_self(var/mob/user)
 	sound_to(owner, 'sound/effects/psi/power_fail.ogg')
 	user.drop_from_inventory(src)