[MIRROR] Fix roundstart seed and fish asset runtimes [MDB IGNORE] (#17727)

* Fix roundstart seed and fish asset runtimes (#71452)

## About The Pull Request

Fixes annoying roundstart runtimes coming from a wrong deduplication
method. `sprites[id]` was empty at the time of the check and only got
filled when it started actually building the spritesheet. Now it's
tracked in a local variable.

No changelog update since it's not visible on the player side.

* Fix roundstart seed and fish asset runtimes

Co-authored-by: disappointedButNotSuprised <57324037+disappointedButNotSuprised@users.noreply.github.com>

code/modules/asset_cache/assets/fish.dm

@@ -2,13 +2,15 @@
 	name = "fish"
 
 /datum/asset/spritesheet/fish/create_spritesheets()
+	var/list/id_list = list()
 	for (var/path in subtypesof(/obj/item/fish))
 		var/obj/item/fish/fish_type = path
 		var/fish_icon = initial(fish_type.icon)
 		var/fish_icon_state = initial(fish_type.icon_state)
 		var/id = sanitize_css_class_name("[fish_icon][fish_icon_state]")
-		if(sprites[id]) //no dupes
+		if(id in id_list) //no dupes
 			continue
+		id_list += id
 		Insert(id, fish_icon, fish_icon_state)
 
 

code/modules/asset_cache/assets/seeds.dm

@@ -2,11 +2,13 @@
 	name = "seeds"
 
 /datum/asset/spritesheet/seeds/create_spritesheets()
+	var/list/id_list = list()
 	for (var/path in subtypesof(/obj/item/seeds))
 		var/obj/item/seeds/seed_type = path
 		var/icon = initial(seed_type.icon)
 		var/icon_state = initial(seed_type.icon_state)
 		var/id = sanitize_css_class_name("[icon][icon_state]")
-		if(sprites[id]) //no dupes
+		if(id in id_list) //no dupes
 			continue
+		id_list += id
 		Insert(id, icon, icon_state)