async function simpleSSOLoginDisabledMiddleware(_, response, next) {
  if (!("multiUserMode" in response.locals)) {
    const multiUserMode = await SystemSettings.isMultiUserMode();
    response.locals.multiUserMode = multiUserMode;
  }

  if (response.locals.multiUserMode && simpleSSOLoginDisabled()) {
    response.status(403).json({
      success: false,
      error: "Login via credentials has been disabled by the administrator.",
    });
    return;
  }
  next();
}
Middleware that checks if simple SSO login is disabled by checking if the
SIMPLE_SSO_NO_LOGIN environment variable is set as well as
SIMPLE_SSO_ENABLED is set.

This middleware will 403 if SSO is enabled and no login is allowed and
the system is in multi-user mode. Otherwise, it will call next.

@param {import("express").Request} request
@param {import("express").Response} response
@param {import("express").NextFunction} next
@returns {void}