Add stable/2026.1 job

The branch was cut, so should be tested.

Change-Id: I5776f81a01814b03e645baee25fcd67d77d91e04
Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>
diff --git a/.zuul.yaml b/.zuul.yaml
index 44c784f..053c572 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -35,6 +35,12 @@
         post-config: {}
 
 - job:
+    name: keystone-tempest-2026-1
+    parent: keystone-tempest
+    nodeset: openstack-single-node-noble
+    override-checkout: stable/2026.1
+
+- job:
     name: keystone-tempest-2025-2
     parent: keystone-tempest
     nodeset: openstack-single-node-noble
@@ -62,6 +68,7 @@
         - keystone-tempest-federation:
             voting: false
         - keystone-tempest-federation-k2k
+        - keystone-tempest-2026-1
         - keystone-tempest-2025-2
         - keystone-tempest-2025-1
         - keystone-tempest-2024-2