This removes the usage of EngineFacade which is a alias for LegacyEngineFacade that is being removed in [1]. This moves to using correct reader and writer sessions as exposed by oslo.db This removes the custom retry code for deadlock and instead uses the implementation in oslo.db [1] https://review.opendev.org/c/openstack/oslo.db/+/798135 Change-Id: I40cea41b0205c058d091e79ab735f4da03aff071 Signed-off-by: Dmitriy Rabotyagov <noonedeadpunk@gmail.com>