Drop redundant index on ci_pipelines.project_id
According to https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/8823, there
are numerous redundant indexes for index_ci_pipelines_on_project_id
:
index_ci_pipelines_on_project_id_and_id_desc
index_ci_pipelines_on_project_id_and_ref_and_status_and_id
index_ci_pipelines_on_project_id_and_sha
index_ci_pipelines_on_project_id_and_source
index_ci_pipelines_on_project_id_and_status_and_config_source
index_ci_pipelines_on_project_id_and_status_and_updated_at
index_ci_pipelines_on_project_idandrefandiddesc
This index is taking 3+ GB, so let's drop it.
Edited by Stan Hu