Sync validate foreign key for ci_pipelines

What does this MR do and why?

This is the second migration to validate the foreign key for ci_pipelines async created synchronously in !132609 (merged)

See https://docs.gitlab.com/ee/development/database/add_foreign_key_to_existing_column.html#add-a-migration-to-validate-the-fk-synchronously

See the following output from postgres.ai that the foreign key validation is completed on prod:

Foreign-key constraints:
    "fk_190998ef09" FOREIGN KEY (external_pull_request_id) REFERENCES external_pull_requests(id) ON DELETE SET NULL
    "fk_262d4c2d19" FOREIGN KEY (auto_canceled_by_id) REFERENCES ci_pipelines(id) ON DELETE SET NULL
    "fk_3d34ab2e06" FOREIGN KEY (pipeline_schedule_id) REFERENCES ci_pipeline_schedules(id) ON DELETE SET NULL
    "fk_67e4288f3a" FOREIGN KEY (auto_canceled_by_id_convert_to_bigint) REFERENCES ci_pipelines(id) ON DELETE SET NULL
    "fk_d80e161c54" FOREIGN KEY (ci_ref_id) REFERENCES ci_refs(id) ON DELETE SET NULL

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Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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Related to #422809 (closed)