fixes foam dart gc issues (#20273)

* fixes foam dart gc issues

* meh

code/modules/projectiles/ammunition/ammo_casings.dm

@@ -329,10 +329,9 @@
 
 /obj/item/ammo_casing/caseless/fire(atom/target as mob|obj|turf, mob/living/user as mob|obj, params, distro, quiet, zone_override = "", spread, atom/firer_source_atom)
 	if(..())
-		loc = null
-		return 1
-	else
-		return 0
+		qdel(src)
+		return TRUE
+	return FALSE
 
 /obj/item/ammo_casing/caseless/a75
 	desc = "A .75 bullet casing."