message: fix(Toast): add mask option deprecation warning
diff: @@ -97,6 +97,12 @@ function Toast(options = {}) {
  ...options,
  };
  + if (process.env.NODE_ENV !== 'production' && options.mask) {
  + console.warn(
  + '[Vant] Toast: "mask" option is deprecated, use "overlay" option instead.'
  + );
  + }
  +
  options.clear = () => {
  toast.value = false;
  