React-markdown isn't rendering phone number links anymore

[aligreene]

Initial checklist

• [X] I read the support docs
• [X] I read the contributing guide
• [X] I agree to follow the code of conduct
• [X] I searched issues and couldn’t find anything (or linked relevant results below)

Affected packages and versions

react-markdown v9.0.0

Link to runnable example

https://codesandbox.io/p/devbox/react-markdown-telephone-link-bug-3vsqry

Steps to reproduce

We recently updated from react-markdown ^8.0.3 to ^9.0.0 and since then, any phone link renders with no value in the link href.

See sandbox for runnable example, or follow steps below:

1. Create a markdown telephone link e.g.: [123 456 789](tel:123456789)
2. Check the output.

Expected behavior

The link is rendered in HTML with a href value: <a href="tel:123456789">123 456 789</a>

Actual behavior

The link renders without a href value: <a href="">123 456 789</a>

Runtime

No response

Package manager

No response

OS

No response

Build and bundle tools

No response