fix: Make chaosOnRestart test more reliable (#985)

- Reduce resource count from 50 to 5 to reduce non-determinism
- Wait for b2's semaphores to start before releasing them
- Use waitForCompletion() and assertBuildStatusSuccess() for
  proper build completion verification instead of waitForMessage()

The test was flaky due to timing issues with 50 parallel resources
and nested locks across 3 builds resuming after Jenkins restart.

Author: mPokornyETM

src/test/java/org/jenkins/plugins/lockableresources/LockStepWithRestartTest.java

@@ -201,7 +201,9 @@ void checkQueueAfterRestart() throws Throwable {
 
     @Test
     void chaosOnRestart() throws Throwable {
-        final int resourceCount = 50;
+        // Reduced from 50 to 5 resources to make the test more deterministic
+        // while still testing the same restart scenarios with parallel stages
+        final int resourceCount = 5;
         sessions.then(j -> {
             for (int i = 1; i <= resourceCount; i++) {
                 LockableResourcesManager.get().createResourceWithLabel("resource" + i, "label");
@@ -238,13 +240,15 @@ void chaosOnRestart() throws Throwable {
             WorkflowRun b2 = p.getBuildByNumber(2);
             WorkflowRun b3 = p.getBuildByNumber(3);
 
-            // Unlock resources
+            // Unlock resources for b1
             for (int i = 1; i <= resourceCount; i++) {
                 SemaphoreStep.success("wait-inside-lockOrderRestart-" + i + "/1", null);
             }
             j.waitForMessage("Lock released on resource [Resource: resource" + resourceCount + "]", b1);
             j.waitForMessage("Lock acquired on [Resource: resource" + resourceCount + "]", b2);
             j.assertLogContains("[resource" + resourceCount + "] is locked by build " + b1.getFullDisplayName(), b3);
+            // Wait for b2 to reach all semaphores before releasing them
+            SemaphoreStep.waitForStart("wait-inside-lockOrderRestart-" + resourceCount + "/2", b2);
             for (int i = 1; i <= resourceCount; i++) {
                 SemaphoreStep.success("wait-inside-lockOrderRestart-" + i + "/2", null);
             }
@@ -253,7 +257,13 @@ void chaosOnRestart() throws Throwable {
             for (int i = 1; i <= resourceCount; i++) {
                 SemaphoreStep.success("wait-inside-lockOrderRestart-" + i + "/3", null);
             }
-            j.waitForMessage("Finish", b3);
+            // Wait for all builds to complete
+            j.waitForCompletion(b1);
+            j.waitForCompletion(b2);
+            j.waitForCompletion(b3);
+            j.assertBuildStatusSuccess(b1);
+            j.assertBuildStatusSuccess(b2);
+            j.assertBuildStatusSuccess(b3);
         });
     }
 }