refactor: convert default-html to a function component (#11146)
refactor: convert default-html to a function component (#11146)

## Description

Refactor the `<HTML />` component into a function component instead of a class component.

## Related Issues
 N/A


ChristopherBiscardi/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,ChristopherBiscardi/gatsby,ChristopherBiscardi/gatsby,gatsbyjs/gatsby,ChristopherBiscardi/gatsby