Switched the mechanism to collect test reports from pipeline builds

In case 'junitReport' are invoked multiple times, avoid overreporting.
See https://cloudbees.atlassian.net/wiki/spaces/PRODUCT/pages/4757815355/Investigation+The+issue+of+multiple+posts+being

src/main/java/io/jenkins/plugins/launchable/RunListenerImpl.java

@@ -0,0 +1,40 @@
+package io.jenkins.plugins.launchable;
+
+import hudson.Extension;
+import hudson.model.listeners.RunListener;
+import org.jenkinsci.plugins.workflow.flow.GraphListener;
+import org.jenkinsci.plugins.workflow.job.WorkflowRun;
+
+import javax.inject.Inject;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.*;
+
+/**
+ * Records test results reported into {@link WorkflowRun}.
+ *
+ * <p>
+ * Our earlier attempt to implement {@link GraphListener} backfired, as when 'junitReport' step was called
+ * multiple times, we end up reporting all test results accumulated up to that point, resulting in duplicate
+ * data reporting.
+ *
+ * <p>
+ * This approach defers the data ingestion all the way down to the end of a workflow run.
+ */
+@Extension
+public class RunListenerImpl extends RunListener<WorkflowRun> {
+    @Inject
+    Ingester ingester;
+
+    @Override
+    public void onFinalized(WorkflowRun run) {
+        try {
+            ingester.slurp(run.getRootDir(), new PropsBuilder<>(run));
+        } catch (Exception e) {
+            // Priority #1: Do no harm to people's build
+            LOGGER.log(WARNING, "Failed to send JUnit result to Launchable", e);
+        }
+    }
+
+    private static final Logger LOGGER = Logger.getLogger("io.jenkins.plugins.launchable.RunListenerImpl");
+}