Add periodic job for single processor node testing

.ci/jobs.t/elastic+elasticsearch+periodic+single-processor-node-tests.yml

@@ -0,0 +1,16 @@
+---
+- job:
+    name: elastic+elasticsearch+%BRANCH%+periodic+single-processor-node-tests
+    display-name: "elastic / elasticsearch # %BRANCH% - single processor node tests"
+    description: "Testing with node.processors set to '1' for the Elasticsearch %BRANCH% branch.\n"
+    node: "general-purpose && docker"
+    builders:
+      - inject:
+          properties-file: '.ci/java-versions.properties'
+          properties-content: |
+            JAVA_HOME=$HOME/.java/$ES_BUILD_JAVA
+            RUNTIME_JAVA_HOME=$HOME/.java/$ES_RUNTIME_JAVA
+            JAVA11_HOME=$HOME/.java/java11
+      - shell: |
+          #!/usr/local/bin/runbld --redirect-stderr
+          $WORKSPACE/.ci/scripts/run-gradle.sh -Dbwc.checkout.align=true -Dtests.configure_test_clusters_with_one_processor=true check

.ci/jobs.t/elastic+elasticsearch+periodic+single-processor-tests-trigger.yml

@@ -0,0 +1,6 @@
+---
+jjbb-template: periodic-trigger-lgc.yml
+vars:
+  - periodic-job: elastic+elasticsearch+%BRANCH%+periodic+single-processor-node-tests
+  - lgc-job: elastic+elasticsearch+%BRANCH%+intake
+  - cron: "H H/12 * * *"