Maybe fix sound token hard deletes (#96903)

## About The Pull Request

`remove_listener` would fail on logout so instead I figure we could
track the tokens on the mob, rather than the client

Functionally not much is changed - but if you go from ghost to mob it'll
remove the token from the ghost and adds the token to the new mob, so it
should fix the issue

There also doesn't need to be any code in `/mob/destroy` because we
listen for `listener_deleted` and remove listeners on the token itself

code/controllers/subsystem/sound_tokens.dm

@@ -15,10 +15,7 @@ SUBSYSTEM_DEF(sound_tokens)
 		var/client/client = currentrun[currentrun.len]
 		currentrun.len--
 		var/mob/owned_mob = client.mob
-		if(!owned_mob)
-			continue
-		for(var/datum/sound_token/token in client.sound_tokens)
+		for(var/datum/sound_token/token as anything in owned_mob?.sound_tokens)
 			token.update_listener(owned_mob)
 		if(MC_TICK_CHECK)
 			break
-