[E2E] PROMOTE TO BLOCKING: import_github_repo_spec.rb

What does this MR do?

Promotes the following e2e tests to the blocking bucket:

1. Manage GitHub import when imported via api imports project | Testcase | Spec metrics

This MR was created based on data from reliable e2e test report: #493073 (closed)

(This MR was automatically generated by gitlab_quality-test_tooling at 2024-09-23 02:08:31 UTC)