Do not show not existed starred repositories

[juev]

We have several repositories, what we added to starred, but now these repositories is not available, for example:

• leominov/gitlab_activity_exporter
• leominov/gitlab_license_exporter
• juev/foam

Maybe these repositories changed visibility?

We should check all starred repositories, what it exist and public for all users.

[juev]

curl -I https://github.com/andmetoo/dot
  HTTP/2 404

curl -I https://github.com/ihciah/shadow-tls
  HTTP/2 200

[juev]

we have a lot 429 errors: 5014131092