
The Neutron method ``alter_enum`` has been removed in [1]. Use ``alembic.op.alter_column`` instead. This migration won't be compatible with PostgreSQL. This patch is also removing the functional tests using PostgreSQL. [1]https://review.opendev.org/c/openstack/neutron/+/934171 Change-Id: Ideafb3a2a92868a5e8b86390a27bf930ae617d0d