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.

Note that this patch was written using this one as example:
https://review.opendev.org/c/openstack/magnum/+/858374

Also include Zuul gate fix. Fix as described in [1][2]

[1] https://lists.opendev.org/pipermail/service-announce/2022-September/000044.html
[2] https://lists.zuul-ci.org/pipermail/zuul-discuss/2022-May/001801.html

Change-Id: I963e741078514b1cca6ed0e510cefaeccdd3499a

.zuul.yaml

@@ -1,4 +1,5 @@
 - project:
+    queue: murano
     templates:
       - check-requirements
       - openstack-cover-jobs
@@ -14,7 +15,6 @@
         - murano-grenade
         - murano-tempest-api-ipv6-only
     gate:
-      queue: murano
       jobs:
         - murano-tempest-api
         - murano-tempest-api-ipv6-only

murano/db/session.py

@@ -37,6 +37,9 @@ def _create_facade_lazily():
     global _LOCK, _FACADE
 
     if _FACADE is None:
+        # FIXME(zigo): autocommit=True it's not compatible with
+        # SQLAlchemy 2.0, and will be removed in future
+        _FACADE = db_session.EngineFacade.from_config(CONF, autocommit=True)
         with _LOCK:
             if _FACADE is None:
                 _FACADE = db_session.EngineFacade.from_config(CONF,