`<script type="module">` results in `data:module;base64,...`

[css-optivoy]

Input tags like <script type="module" src="..."></script> result in output tags like <script crossorigin="" src="data:module;base64,..."></script> which doesn't seem valid nor loads in Chrome.

I don't believe module is a valid MIME type, and if I edit the output file to use text/javascript instead, the file loads fine.