Simpler two queries than one JOIN with subquery
This is a follow up from !5347
Originally it was:
``` ruby
pipeline = pipelines.latest_successful_for(ref)
builds.where(pipeline: pipeline).latest.with_artifacts
```
However MySQL would complain that we can't use `IN` against a subquery which has `LIMIT`. Using `INNER JOIN` would be a workaround, however, doing that is too complicated in current version of Rails.
So let's just use two queries in this case.
Closes#14419
See merge request !5388