django: remove unused DatabaseWrapper.data_types_check_constraints (#441)
django: remove unused DatabaseWrapper.data_types_check_constraints (#441)

The proper name is data_type_check_constraints (no 's' after type) but
Spanner doesn't have check constraints anyway.

Co-authored-by: Emmanuel T Odeke <bd234ba4276433f0e5fc7a8fa2d18274fa711567@orijtech.com>
googleapis/python-spanner-django,googleapis/python-spanner-django