Yoshi's Island: add patch suffix (ArchipelagoMW#3061)

Author: Silvris

worlds/yoshisisland/Client.py

@@ -36,6 +36,7 @@
 
 class YoshisIslandSNIClient(SNIClient):
     game = "Yoshi's Island"
+    patch_suffix = ".apyi"
 
     async def deathlink_kill_player(self, ctx: "SNIContext") -> None:
         from SNIClient import DeathState, snes_buffered_write, snes_flush_writes, snes_read