I went through the validation process for jammy-zed UCA successfully, here it's the evidence:

$ juju ssh magnum/0 "apt policy python3-magnum"
python3-magnum:
  Installed: 15.0.1-0ubuntu1~cloud0
  Candidate: 15.0.1-0ubuntu1~cloud0
  Version table:
 *** 15.0.1-0ubuntu1~cloud0 500
        500 http://ubuntu-cloud.archive.canonical.com/ubuntu jammy-proposed/zed/main amd64 Packages
        100 /var/lib/dpkg/status
     14.1.0-0ubuntu1 500
        500 http://nova.clouds.archive.ubuntu.com/ubuntu jammy-updates/universe amd64 Packages
     14.0.0-0ubuntu1 500
        500 http://nova.clouds.archive.ubuntu.com/ubuntu jammy/universe amd64 Packages
Connection to 10.5.3.115 closed.

$ tox -e func-target -- keystone_v3_smoke_focal_magnum:jammy-zed-magnum
func-target: commands[0] /mnt/git/charmed-openstack-tester/tests/distro-regression> functest-run-suite --keep-model --bundle keystone_v3_smoke_focal_magnum:jammy-zed-magnum
2023-05-22 00:45:09 [INFO] Deploying bundle '/mnt/git/charmed-openstack-tester/tests/distro-regression/tests/bundles/jammy-zed-magnum.yaml' on to 'zaza-3c14612ee9e8' model
2023-05-22 00:45:10 [INFO] Rendered template '<Template 'local-charm-overlay.yaml.j2'>' to file '/tmp/tmpmjyndp00/local-charm-overlay.yaml'
2023-05-22 00:45:11 [INFO] Rendered template '<Template 'jammy-zed-magnum.yaml.j2'>' to file '/tmp/tmpmjyndp00/jammy-zed-magnum.yaml'
2023-05-22 00:45:11 [INFO] Deploying overlay '/tmp/tmpmjyndp00/local-charm-overlay.yaml' on to 'zaza-3c14612ee9e8' model
2023-05-22 00:45:11 [INFO] Deploying overlay '/tmp/tmpmjyndp00/jammy-zed-magnum.yaml' on to 'zaza-3c14612ee9e8' model
...
======
Totals
======
Ran: 120 tests in 1472.0181 sec.
 - Passed: 111
 - Skipped: 9
 - Expected Fail: 0
 - Unexpected Success: 0
 - Failed: 0
Sum of execute time for each test: 865.2561 sec.

==============
Worker Balance
==============
 - Worker 0 (120 tests) => 0:24:32.018097
2023-05-22 02:20:37 [INFO] Finished testing zaza-3c14612ee9e8                                                                                                                                 [45/1387]
2023-05-22 02:20:37 [INFO] Events:
  Configure zaza.openstack.charm_tests.glance.setup.add_cirros_alt_image:
    Start: 1684720314.4487019
    Finish: 1684720322.1496775
    Elapsed Time: 7.700975656509399
    PCT Of Run Time: 1
  Configure zaza.openstack.charm_tests.glance.setup.add_cirros_image:
    Start: 1684720306.46469
    Finish: 1684720314.4484348
    Elapsed Time: 7.983744859695435
    PCT Of Run Time: 1
  Configure zaza.openstack.charm_tests.glance.setup.add_lts_image:
    Start: 1684720015.861922
    Finish: 1684720096.5621715
    Elapsed Time: 80.70024943351746
    PCT Of Run Time: 2
  Configure zaza.openstack.charm_tests.glance_simplestreams_sync.setup.sync_images:
    Start: 1684719715.9663482
    Finish: 1684720015.8614337
    Elapsed Time: 299.8950855731964
    PCT Of Run Time: 6
  Configure zaza.openstack.charm_tests.heat.setup.domain_setup:
    Start: 1684720322.1499038
    Finish: 1684720346.6935213
    Elapsed Time: 24.543617486953735
    PCT Of Run Time: 1
  Configure zaza.openstack.charm_tests.keystone.setup.add_demo_user:
    Start: 1684720259.2294688
    Finish: 1684720298.745129
    Elapsed Time: 39.51566028594971
    PCT Of Run Time: 1
  Configure zaza.openstack.charm_tests.keystone.setup.add_tempest_roles:
    Start: 1684720298.7455883
    Finish: 1684720306.4644384
    Elapsed Time: 7.718850135803223
    PCT Of Run Time: 1
  Configure zaza.openstack.charm_tests.magnum.setup.add_image:
    Start: 1684720365.9974182
    Finish: 1684720511.332798
    Elapsed Time: 145.33537983894348
    PCT Of Run Time: 3
  Configure zaza.openstack.charm_tests.magnum.setup.domain_setup:
    Start: 1684720346.6938584
    Finish: 1684720365.9972289
    Elapsed Time: 19.303370475769043
    PCT Of Run Time: 1
  Configure zaza.openstack.charm_tests.neutron.setup.basic_overcloud_network:
    Start: 1684720096.5626245
    Finish: 1684720232.1952615
    Elapsed Time: 135.63263702392578
    PCT Of Run Time: 3
  Configure zaza.openstack.charm_tests.nova.setup.create_flavors:
    Start: 1684720232.1967628
    Finish: 1684720251.9953403
    Elapsed Time: 19.798577547073364
    PCT Of Run Time: 1
  Configure zaza.openstack.charm_tests.nova.setup.manage_ssh_key:
    Start: 1684720251.9957662
    Finish: 1684720259.229309
    Elapsed Time: 7.2335429191589355
    PCT Of Run Time: 1
  Configure zaza.openstack.charm_tests.vault.setup.auto_initialize:
    Start: 1684719271.2652552
    Finish: 1684719715.9652262
    Elapsed Time: 444.69997096061707
    PCT Of Run Time: 8
  Deploy Bundle:
    Start: 1684716309.5860736
    Finish: 1684716504.983315
    Elapsed Time: 195.39724135398865
    PCT Of Run Time: 4
  Prepare Environment:
    Start: 1684716297.7318268
    Finish: 1684716309.584011
    Elapsed Time: 11.852184295654297
    PCT Of Run Time: 1
  Test zaza.openstack.charm_tests.tempest.tests.TempestTestWithKeystoneV3:
    Start: 1684720511.3345678
    Finish: 1684722037.1901364
    Elapsed Time: 1525.8555686473846
    PCT Of Run Time: 27
  Wait for Deployment:
    Start: 1684716504.9834142
    Finish: 1684719241.6091454
    Elapsed Time: 2736.625731229782
    PCT Of Run Time: 48
Metadata: {}

  func-target: OK (5744.89=setup[0.25]+cmd[5744.63] seconds)
  congratulations :) (5745.23 seconds)