Validation for make "strategy:depend" the default for parent-child pipelines

Problem Statement

The question we want to answer is whether users of parent-child pipelines want and expect the parent pipeline to always wait for child pipelines to complete first, so that we can make this a default behavior.

Today not all parent-child pipelines are configured with the strategy:depends syntax which is a strategy that makes the parent pipeline wait for child pipelines to complete before the parent pipeline can complete. When a parent pipeline is configured to list all artifacts produced by itself and its descendant pipelines, the absence of the strategy:depends causes a race condition where the parent pipeline could complete before all the child pipelines have completed. The consequence is as soon as the parent pipeline completes, the MR reports shows an incomplete list of artifacts for those generated by the parent pipeline and by some of its child pipelines, but there are missing artifacts for child pipelines that are still running. Eventually all artifacts are visible in the MR as the remaining child pipelines complete, but until then the MR report is inaccurate due to incompleteness.

Reach

6.0 = Impacts a large percentage (~50% to ~80%) of the above.

Impact

2.0 = High impact

Confidence

80% = Medium confidence

Effort

3 people x .5 months = 1.5 effort