Attribute alt (and image_style) not allowed on element div in HTML5

Problem/Motivation

Attribute alt not allowed on element div in HTML5. This causes errors in HTML validation. If you provide it to Google Search, AMP pages will not appear in search results.

<div data-embed-button="media_browser"
     data-entity-embed-display="media_image"
     data-entity-embed-display-settings="small"
     data-entity-type="media"
     data-entity-uuid="XXXXXXXXXXXX"
     alt="myImageAlt" //This causes errors
     title="myImageTitle"
     data-langcode="ja"
     class="embedded-entity align-center">
    <amp-img src="/sites/default/files/styles/small/public/images/myImage.jpg?itok=XXXXXXXX"
             width="700"
             height="510"
             alt="myImageAlt"
             title="myImageTitle"
             layout="responsive">
    </amp-img>
</div>

Proposed resolution

Remove alt attribute from div element that rendered from <drupal-entity> .

<div data-embed-button="media_browser"
     data-entity-embed-display="media_image"
     data-entity-embed-display-settings="small"
     data-entity-type="media"
     data-entity-uuid="XXXXXXXXXXXX"
     // just removed alt with `attributes.removeAttribute('alt')` in twig.
     title="myImageTitle"
     data-langcode="ja"
     class="embedded-entity align-center">
    <amp-img src="/sites/default/files/styles/small/public/images/myImage.jpg?itok=XXXXXXXX"
             width="700"
             height="510"
             alt="myImageAlt"
             title="myImageTitle"
             layout="responsive">
    </amp-img>
</div>

Remaining tasks

reviews needed