Vue version

3.5.13

Link to minimal reproduction

https://vuejs.org/guide/built-ins/transition-group

Steps to reproduce

The error is visible, if the docs-page for TransitionGroups (https://vuejs.org/guide/built-ins/transition-group) is put through the W3C validator:

Attribute name not allowed on element [ul](https://html.spec.whatwg.org/multipage/#the-ul-element) at this point

What is expected?

Valid HTML

What is actually happening?

Invalid HTML

System Info

Any additional comments?

No response