[CI] Disable tracked branch jobs in Jenkins, enable reporting in Buildkite (elastic#112604)

Author: brianseeders

.buildkite/scripts/lifecycle/post_command.sh

@@ -22,6 +22,5 @@ if [[ "$IS_TEST_EXECUTION_STEP" == "true" ]]; then
   buildkite-agent artifact upload 'x-pack/test/functional/failure_debug/html/*.html'
   buildkite-agent artifact upload '.es/**/*.hprof'
 
-  # TODO - re-enable when Jenkins is disabled
-  # node scripts/report_failed_tests --build-url="${BUILDKITE_BUILD_URL}#${BUILDKITE_JOB_ID}" 'target/junit/**/*.xml'
+  node scripts/report_failed_tests --build-url="${BUILDKITE_BUILD_URL}#${BUILDKITE_JOB_ID}" 'target/junit/**/*.xml'
 fi

Jenkinsfile

@@ -1,5 +1,10 @@
 #!/bin/groovy
 
+if (!env.ghprbPullId) {
+  print "Non-PR builds are now in Buildkite."
+  return
+}
+
 library 'kibana-pipeline-library'
 kibanaLibrary.load()