Add job to test with SQLAlchemy master (2.x)

Signed-off-by: Stephen Finucane <stephenfin@redhat.com>
Change-Id: I44f35fe94bdc48e0db5f414437b1ab018dbb49f2

.zuul.yaml

@@ -187,6 +187,21 @@
       - ^heat/tests/.*$
       - ^releasenotes/.*$
 
+- job:
+    name: heat-tox-py310-with-sqlalchemy-2x
+    parent: openstack-tox-py310
+    description: |
+      Run unit tests with main branch of SQLAlchemy, alembic and oslo.db.
+      Takes advantage of the base tox job's install-siblings feature.
+    # The job only tests the latest and shouldn't be run on the stable branches
+    branches: ^master$
+    required-projects:
+      - name: github.com/sqlalchemy/sqlalchemy
+        override-checkout: main
+      - name: github.com/sqlalchemy/alembic
+        override-checkout: main
+      - name: openstack/oslo.db
+
 - project:
     queue: heat
     templates:
@@ -203,6 +218,7 @@
         - heat-functional
         - heat-functional-legacy
         - heat-functional-centos-9-stream
+        - heat-tox-py310-with-sqlalchemy-2x
     gate:
       jobs:
         - grenade-heat-multinode