Fix compatibility with oslo.db 12.1.0
Fix compatibility with oslo.db 12.1.0

oslo.db 12.1.0 has changed the default value for the 'autocommit'
parameter of 'LegacyEngineFacade' from 'True' to 'False'. This is a
necessary step to ensure compatibility with SQLAlchemy 2.0. However, we
are currently relying on the autocommit behavior and need changes to
explicitly manage sessions. Until that happens, we need to override the
default.

Co-Authored-By: Stephen Finucane <4725dc7f3632bf126d9fbdc30c347e91e8d2fe16@redhat.com>
Change-Id: Ic7c5703c1d1009f6c402766aeb20fa9869495470

openstack/blazar,openstack/blazar