Volto: redirect to login page after logout

[pigeonflight (David Bain (dbain.com))]

Found it.
had to

1. shadow the component customizations/components/manage/Toolbar/PersonalTools.jsx
   volto/packages/volto/src/components/manage/Toolbar/PersonalTools.jsx at main · plone/volto · GitHub

2. Change the logout link to include a return_url=/login

 <Link id="toolbar-logout" to={`${getBaseUrl(pathname)}/logout?return_url=/login`}>
          <Icon
            className="logout"
            name={logoutSVG}
            size="30px"
            title={intl.formatMessage(messages.logout)}
          />
        </Link>

Now, when someone logs out they will always be redirected to the login page.