[E2E] PROMOTE TO BLOCKING: saml_sso_merge_request_approve_spec.rb

What does this MR do?

Promotes the following e2e tests to the blocking bucket:

1. Govern Merge request approval with SAML SSO can be approved when requiring a password | Testcase | Spec metrics

This MR was created based on data from reliable e2e test report: #496265 (closed)

(This MR was automatically generated by gitlab_quality-test_tooling at 2024-09-30 02:06:36 UTC)