Crown updated to use aria-hidden="true"
Crown updated to use aria-hidden="true"

GOV.UK Frontend updated the crown SVG in the header component to use
`aria-hidden="true"` instead of `role="presentation"` - see the commit
https://github.com/alphagov/govuk-frontend/commit/7278efe3d085fab1b637c509cf9262e4d51a4b5d
for more information.

This updates the header in static to do the same thing - `role="presentation"`
has been removed and `aria-hidden="true"` has been added.

alphagov/static,alphagov/static,alphagov/static