Since website based on 2 different repos, there was an inconsistency
in theme selection, so we had 2 independant theme props.
Now only one stored in local storage is a single source of truth
PR-URL: https://github.com/nodejs/node/pull/50877
Reviewed-By: Claudio Wunder <cwunder@gnome.org>
Reviewed-By: Yagiz Nizipli <yagiz.nizipli@sentry.io>