[QUARANTINE] Verify When pipeline is blocked can still merge MR successfully

What does this MR do?

Quarantines the test Verify When pipeline is blocked can still merge MR successfully (https://gitlab.com/gitlab-org/gitlab/-/blob/master/qa/qa/specs/features/browser_ui/4_verify/pipeline/merge_mr_when_pipline_is_blocked_spec.rb#L71)

This test has been found by Confiner to have been failing for more than (or equal to) 3 times. This test has failed 3 times.

1. ee:praefect-parallel
2. ee:instance-parallel
3. ee:instance-parallel

#352194 (closed)

(This MR was automatically generated by Confiner at 2022-02-08 01:17:24 UTC)