[385649] Rollout FF github_client_fetch_repos_via_graphql

What does this MR do and why?

Rollouts (removes) github_client_fetch_repos_via_graphql feature flag

Testing screenshots/videos

Click to expand

NOTE: I set Import::GithubController::PAGE_LENGTH to 5

How to set up and validate locally

Go to the import GitHub page and see the list of repos. You could also decrease Import::GithubController::PAGE_LENGTH for better pagination testing.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.