Merge branch 'preload-downstream-pipeline-for-commit-statuses' into 'master'

Preload downstream_pipeline in CommitStatusPreloader

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/142199



Merged-by: Allison Browne <abrowne@gitlab.com>
Approved-by: Allison Browne <abrowne@gitlab.com>
Reviewed-by: Allison Browne <abrowne@gitlab.com>
Reviewed-by: Max Fan <mfan@gitlab.com>
Co-authored-by: Hordur Freyr Yngvason <hfyngvason@gitlab.com>