Fix 'available' KeyError for GuildSticker

Co-authored-by: Danny <[email protected]>

discord/sticker.py

@@ -436,7 +436,7 @@ class GuildSticker(Sticker):
 
     def _from_data(self, data: GuildStickerPayload) -> None:
         super()._from_data(data)
-        self.available: bool = data['available']
+        self.available: bool = data.get('available', True)
         self.guild_id: int = int(data['guild_id'])
         user = data.get('user')
         self.user: Optional[User] = self._state.store_user(user) if user else None

discord/types/sticker.py

@@ -55,7 +55,7 @@ class StandardSticker(BaseSticker):
 
 class GuildSticker(BaseSticker):
     type: Literal[2]
-    available: bool
+    available: NotRequired[bool]
     guild_id: Snowflake
     user: NotRequired[User]