Fix type sig

Co-authored-by: Niklas van Schrick <[email protected]>

sig/code0/identities/provider/discord.rbs

@@ -4,7 +4,7 @@ module Code0
       class Discord < BaseOauth
         def token_url: () -> "https://discord.com/api/oauth2/token"
 
-        def token_payload: (untyped code) -> { code: String, grant_type: "authorization_code", redirect_uri: String, client_id: String, client_secret: String }
+        def token_payload: (code: String) -> { code: String, grant_type: "authorization_code", redirect_uri: String, client_id: String, client_secret: String }
 
         def user_details_url: () -> "https://discord.com/api/users/@me"