Remove "Retry all failed jobs" button from Merge Train pipelines
Summary
The pipeline list shows the "retry all failed jobs" button next to pipelines when any job in the pipeline fails, but this should not be available for merge train pipelines. No jobs in merge train pipelines can be manually retried, so this button should be removed.
Screenshot:
In fact, testing this button seems to do nothing, though it makes it appear as if the pipeline is running. No jobs restart, and no jobs are running, but the cancel button now appears, which doesn't make sense.
Proposal
Remove the button from any pipeline list that could show it, including the main pipeline list page and merge request pipelines tab.