[PROMOTE TO BLOCKING] Create Merge request rebasing user rebases source branch of merge request

What does this MR do?

Promotes the test Create Merge request rebasing user rebases source branch of merge request to the blocking bucket

This test was identified in the reliable e2e test report: #442287 (closed)

(This MR was automatically generated by gitlab_quality-test_tooling at 2024-02-19 02:05:33 UTC)