[tacker] Transition Train to End of Life

With the new resolution '2023-07-24 Unmaintained status replaces
Extended Maintenance' [1] the last 3 EM branches (Xena, Wallaby,
Victoria) will transition to Unmaintained, but older branches (Ussuri,
Train) should move to End of Life unless someone steps up as maintainer
of this branch for this project.

To signal this, please add a -1 for this patch if you or the team want
to keep this branch open for further maintenance.
If there is no response from anyone within a reasonable time frame,
then PTLs/release liaisons will be asked to confirm the EOL transition
with their +1.

[1] https://governance.openstack.org/tc/resolutions/20230724-unmaintained-branches.html

Change-Id: I01778d81205f47ef7dfa6366ab4a5af3b93e6128

deliverables/train/tacker-horizon.yaml

@@ -14,6 +14,10 @@ releases:
     projects:
       - repo: openstack/tacker-horizon
         hash: e0e3836b4b667f0449aba1b51279b76e69ae7a44
+  - version: train-eol
+    projects:
+      - repo: openstack/tacker-horizon
+        hash: c82bf027a1590d0591c69fa2f98473df2baf5186
 branches:
   - name: stable/train
     location: 0.15.0