Adds a holiday-exclusive mail pool (#90437)

## About The Pull Request
Holidays with mail allowed are now able to have a pool of mail goodies
associated with them.

(If anyone has any ideas I missed please do tell me them. Ones I really
wanted to add are things for Ramadan and Hanukkah but I both don't know
enough about them and also don't know any traditional Islamic/Jewish
foods/trinkets we have in our codebase)
## Why It's Good For The Game
Adds more flavor to the game's various holidays.
## Changelog
🆑 Wallem
add: Some holidays have been given their own pool of mail goodies.
/🆑

---------

Co-authored-by: Ghom <42542238+Ghommie@users.noreply.github.com>
Co-authored-by: carlarctg <53100513+carlarctg@users.noreply.github.com>

code/modules/hydroponics/grown/banana.dm

@@ -205,3 +205,14 @@
 	if(!is_simian(user))
 		return to_chat(user, span_notice("You don't really know what to do with this."))
 	else start_ripening()
+
+/// Used for april fools mail
+/obj/item/grown/bananapeel/gros_michel
+	name = "gros michel peel"
+	desc = "A peel from a species of banana that's hyper-vulnerable to contamination."
+
+/obj/item/grown/bananapeel/gros_michel/Initialize(mapload)
+	. = ..()
+	AddComponent(/datum/component/germ_sensitive, mapload)
+	transform *= 1.25
+	AddComponent(/datum/component/decomposition, mapload, decomp_req_handle = TRUE, custom_time = 1 MINUTES, decomp_result = /obj/item/food/badrecipe/moldy)