The sync engine fixture (engine) and async engine fixture (db_engine) now
iterate all Base.metadata tables and null server_default on any column
whose SQL text contains 'gen_random_uuid' or 'gen_random_bytes'. This
covers all UUIDPrimaryKeyMixin columns (Purchase, PurchaseItem, Store,
StoreLocation, Coupon, NormalizedProduct, PriceHistory,
ShrinkflationEvent, UserStoreAccount) as well as the
email_inbound_token gen_random_bytes expression in User.
Without this, SQLite raises 'type UUID is not supported' when the ORM
tries to bind Python UUID objects, and NOT NULL constraint failures when
server_default expressions reference non-existent PostgreSQL functions.
Co-Authored-By: Paperclip <noreply@paperclip.ing>