HTML validation error: "The button role is unnecessary for element button."

[hannalaakso]

The header with navigation component sets role="button" on the menu button.

Our button component doesn’t set this attribute but the header button is hardcoded.

<button> is well supported so setting role is not useful here.

The W3C Markup Validator flags it as warning

The button role is unnecessary for element button.

We could also consider using our button macro here - if we decide to make it possible to override govuk-button class on the component since the header button won’t be requiring those styles.