fix(gatsby): remove role alert on gatsby-announcer (#20914)

remove role alert from announcer live region

Author: madalynrose

packages/gatsby/cache-dir/navigation.js

@@ -199,7 +199,6 @@ class RouteAnnouncer extends React.Component {
           whiteSpace: `nowrap`,
           border: 0,
         }}
-        role="alert"
         aria-live="assertive"
         aria-atomic="true"
         ref={this.announcementRef}