CSB embed editor does not properly highlight `<script type="module">`

🐛 bug report

Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project
  adheres to.
• I have searched the issue tracker for an issue that matches the one I want
  to file, without success.

Description of the problem

I just updated a Redux docs vanilla JS example sandbox to go from a plain <script> tag to a <script type="module">. Now, the embed editor no longer does any syntax highlighting for the JS code in that script tag:

• https://redux.js.org/tutorials/fundamentals/part-1-overview#redux-core-example-app
• https://codesandbox.io/s/redux-fundamentals-core-example-lr7k1?from-embed=&file=/index.html

The code highlights correctly in the full CSB editor:

How has this issue affected you? What are you trying to accomplish?

This is a bare basic example of Redux usage with vanilla JS, to illustrate the concepts.

Lack of syntax highlighting isn't a total breaking issue, but it's definitely annoying and makes it harder for Redux learners to read the code in this example.

To Reproduce

• Browse to the Redux docs at https://redux.js.org/tutorials/fundamentals/part-1-overview#redux-core-example-app and observe the highlighting in the <script> tag in the sandbox embed

Link to sandbox: https://codesandbox.io/s/redux-fundamentals-core-example-lr7k1?from-embed=&file=/index.html

Reproduce the issue in the linked Redux documentation sandbox, focusing on the embedded editor's handling of the <script type="module"> tag. Compare its highlighting with the full CSB editor shown in the report. Done means JavaScript inside module script tags is highlighted correctly in the embed editor.