https://gitlab.com/gitlab-org/gitlab/merge_requests/20615 introduced a
performance regression: each failed build would generate additional SQL
queries, since they would be rendered by JobEntity. This commit fixes
that by preloading failed builds among other items and adds an N+1 query
test. This adds 4 additional queries per pipeline:

1. user
2. latest_statuses_ordered_by_stage
3. failed_builds
4. failed_builds metadata

Closes https://gitlab.com/gitlab-org/gitlab/issues/118427