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

Change-Id: I3486492c00b8294bfe67fa81a09d6f241f1a6057
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

.zuul.yaml

@@ -1,3 +1,19 @@
+# Temporary job until SQLAlchemy 2.0 is no longer blocked by upper-requirements
+- job:
+    name: taskflow-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: ^(?!stable)
+    required-projects:
+      - name: github.com/sqlalchemy/sqlalchemy
+        override-checkout: main
+      - name: github.com/sqlalchemy/alembic
+        override-checkout: main
+      - name: openstack/oslo.db
+
 - project:
     templates:
       - check-requirements
@@ -7,3 +23,9 @@
       - periodic-stable-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
+    check:
+      jobs:
+        - taskflow-tox-py310-with-sqlalchemy-2x
+    gate:
+      jobs:
+        - taskflow-tox-py310-with-sqlalchemy-2x