Update Form API #ajax['progress']['type'] documentation

Does it still support none? In ajax.js I see this

Type of progress element, core provides `'bar'`, `'throbber'` and
`'fullscreen'`.

Or is that another spot that could be updated?

Huh. I recall using 'none' to hide it. Though now I am not finding much on that. I see scatterings of things mentioning it, like this from 2017: https://drupalsun.com/unknown/2017/01/08/disable-ajax-throbber

Is it possible that passing 'none' results in nothing happening here?

   if (!this.progress || !this.progress.type) {
      return;
    }

    // Insert progress indicator.
    const progressIndicatorMethod = `setProgressIndicator${this.progress.type
      .slice(0, 1)
      .toUpperCase()}${this.progress.type.slice(1).toLowerCase()}`;
    if (
      progressIndicatorMethod in this &&
      typeof this[progressIndicatorMethod] === 'function'
    ) {
      this[progressIndicatorMethod].call(this);
    }

typeof this[progressIndicatorMethod] === 'function' would be FALSE if anything other than the listed ones are passed, right?

That's the way I read it.

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