Project: get_latest_build and prefetch use different queries

[agjohnson]

Noticed and partially fixed in #12225, these two methods can result in different queries to the list of builds:

• Project.objects.get(pk=123).get_latest_build()
• Project.objects.prefetch_latest_build().get(pk=123).get_latest_build()

This is because get_latest_build() uses a different query filter and takes a finished=True argument by default, however when using prefetch the query filter is different and completely discards the fishined argument.

The get_latest_build() method is not used in many places and mostly just from templates. We could either make the query match when using/not using prefetch, or just only allow this method when builds are prefetched -- throwing an exception otherwise. I didn't chase down a solution to this, I was working on an unrelated fix.

[stsewd]

This was fixed in #12400