Add support for a new vendor API version to an existing Data warehouse import source, or deprecate an old one. Use when a vendor ships a new API version (Stripe date versions, Shopify quarterly versions, header-pinned revisions, /vN/ URL bumps), when implementing a version-update or deprecation task for a source under products/warehouse_sources/backend/temporal/data_imports/sources, or when repinning an ExternalDataSource to a different version. Covers deciding whether a newly announced version needs supporting at all, version declaration, dispatch, pinning semantics, deprecation metadata, and migration scripts.