Add Gerrit User Summit 2026 pipeline

Build the Gerrit User Summit 2026 website
and publish it automatically upon changes on the
summit/2026 repository.

Change-Id: I1d948adba0be28ca19f5551b4019cab17ee9ef11

jenkins-internal/summit-2026.yaml

diff --git a/jenkins-internal/summit-2026.yaml b/jenkins-internal/summit-2026.yaml
new file mode 100644
index 0000000..ce8b65a
--- /dev/null
+++ b/jenkins-internal/summit-2026.yaml
@@ -0,0 +1,14 @@
+- job:
+    name: summit-2026
+    project-type: pipeline
+    disabled: true
+    pipeline-scm:
+      scm:
+        - git:
+            credentials-id: gerrit.googlesource.com
+            url: https://gerrit.googlesource.com/a/summit/2026
+            branches:
+              - master
+    triggers:
+      - pollscm:
+          cron: "H/20 * * * *"