[E2E] PROMOTE TO BLOCKING: push_mirroring_over_http_spec.rb

What does this MR do?

Promotes the following e2e tests to the blocking bucket:

1. Create Push mirror a repository over HTTP configures and syncs a (push) mirrored repository | Testcase | Spec metrics

This MR was created based on data from reliable e2e test report: #458802 (closed)

(This MR was automatically generated by gitlab_quality-test_tooling at 2024-04-29 18:37:07 UTC)