- Remove duplicate compile-time interface assertion for SQLStore.
- Fix the down migration to drop payment_intents before payments to
respect the foreign key dependency order. This was not a bug in the
first place bc we have the CASCADE when deleting payments.
The 000009 schema version slot is now taken by 000009_graph_v2_columns
which was merged ahead of the payments schema. Bump the payments schema
file number to 000010 to avoid the collision.
Moreover update the migration_dev.go file to reflect this change and
update the order of migration.