On reflection the certificate number only needs to travel through the
address2uprn pipeline (result CSV, S3 output) as an internal value —
not persisted to property. Reverts the PropertyIdentityInsert /
property_table.py / property_postgres_repository.py changes; keeps
certificate_number flowing through get_epc_data_with_postcode,
get_uprn_with_epc_df, get_uprn_from_historic_epc, and the
address2uprn_certificate_number result column.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>