[QUARANTINE] Verify Pipeline editor can switch branches and target branch field updates accordingly

What does this MR do?

Quarantines the test Verify Pipeline editor can switch branches and target branch field updates accordingly (https://gitlab.com/gitlab-org/gitlab/-/blob/master/qa/qa/specs/features/browser_ui/4_verify/pipeline/pipeline_editor_branch_switcher_spec.rb#L69)

This test has been found by Confiner to have failed 4 times, which exceeds the threshold of 3 times.

1. ee:instance-parallel
2. ee:relative_url-parallel
3. ee:update-parallel
4. ee:praefect-parallel

#355295 (closed)

(This MR was automatically generated by Confiner at 2022-03-17 01:17:28 UTC)