Button to convert manual build steps into automatic ones
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### Preface
When a merge request has an associated build running, we have a "merge when build passes" button. This tells GitLab to execute the merge (a typically manual action) once the automated process completes.
### Description
When a manual build step is waiting for a previous build to complete, **I'd like similar functionality** - some button I can press **now** so that GitLab runs the manual action immediately once the automated part is done.
As of now, if I want that manual step to run ASAP, I have to wait on the pipeline screen and mash `[F5]` until the previous steps pass and that "play" button becomes available.
### Proposal
Add a button to "automatically run [manual build step]" when previous steps pass.
Given this pipeline, where `deploy` is the only `manual` step:

I'd like the ability to click something on/near the `deploy` step to schedule its execution ASAP.
### Links / references
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