Returns whether this device has a stored passkey ready to be used for sign-in
function hasStoredPasskey( client: ThirdwebClient, ecosystemId?: `ecosystem.${string}`, storage?: AsyncStorage,): Promise<boolean>;
the thirdweb client
let client: { readonly clientId: string; readonly secretKey: string | undefined;} & Readonly<ClientOptions>;
let ecosystemId: `ecosystem.${string}`;
let storage: { getItem: (key: string) => Promise<null | string>; removeItem: (key: string) => Promise<void>; setItem: (key: string, value: string) => Promise<void>;};
let returnType: Promise<boolean>;
whether the device has a stored passkey