[E2E] PROMOTE TO BLOCKING: restrict_push_protected_branch_spec.rb

What does this MR do?

Promotes the following e2e tests to the blocking bucket:

1. Create Restricted protected branch push and merge when only one user is allowed to merge and push to a protected branch behaves like selected developer user pushes and merges | Testcase | Spec metrics

This MR was created based on data from reliable e2e test report: #462605 (closed)

(This MR was automatically generated by gitlab_quality-test_tooling at 2024-05-20 02:05:33 UTC)