[E2E] PROMOTE TO BLOCKING: log_into_gitlab_via_ldap_spec.rb

What does this MR do?

Promotes the following e2e tests to the blocking bucket:

1. Govern LDAP login user logs into GitLab using LDAP credentials | Testcase | Spec metrics

This MR was created based on data from reliable e2e test report: #463733 (closed)

(This MR was automatically generated by gitlab_quality-test_tooling at 2024-05-27 02:05:55 UTC)