Upgrade sqlalchemy

Adapt code to prevent new warnings and errors (as of SQLAlchemy 1.4):
- Overlapping foreign key columns could be set in a conflicting way
  => This is prevented by the application logic
  => Ignore the warning by setting a `overlaps` flag
- Transaction already rolled back
  => This only happens when tests cause an `IntegrityError` on purpose
  => Filter away the corresponding warning in the fixture
- Query returns `Row` objects and not scalars
  => Add genexpr to pull out `primary_id`

src/urban_meal_delivery/db/customers.py

@@ -67,11 +67,14 @@ class Customer(meta.Base):
             db.session.query(db.Address)
             .filter(
                 db.Address.id.in_(
-                    db.session.query(db.Address.primary_id)  # noqa:WPS221
-                    .join(db.Order, db.Address.id == db.Order.delivery_address_id)
-                    .filter(db.Order.customer_id == self.id)
-                    .distinct()
-                    .all(),
+                    row.primary_id
+                    for row in (
+                        db.session.query(db.Address.primary_id)  # noqa:WPS221
+                        .join(db.Order, db.Address.id == db.Order.delivery_address_id)
+                        .filter(db.Order.customer_id == self.id)
+                        .distinct()
+                        .all()
+                    )
                 ),
             )
             .all()