Remove CI job master-pipeline-status

What does this MR do and why?

The added job has not shown to be helpful in communicating broken master pipelines in MRs so we will revert. We can reconsider adding the job when we find a reliable way to detect a true broken master scenario (a failed master pipeline that's not flaky).

In the mean time I'm going to consider the mentioned option to use triage-ops to detect failure and/or cancel pipelines but that process will be outside the gitlab pipeline when we decide to go with it.

See discussion in Spike: create a job in the `sync` stage and can... (gitlab-org/quality/engineering-productivity/team#419 - closed) for details.

This reverts merge request !144691 (merged)

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