Merge branch 'morefice/cleanup-p-ci-builds-metadata-schema' into 'master'

Clean up p_ci_builds_metadata schema

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/113955



Merged-by: Marius Bobin <mbobin@gitlab.com>
Approved-by: Marius Bobin <mbobin@gitlab.com>
Reviewed-by: Max Orefice <morefice@gitlab.com>
Co-authored-by: Maxime Orefice <morefice@gitlab.com>