Don't fail on BrokenBarrierException

If the barrier has been reset that means the test has already completed and we
don't care about node connection attempts and shouldn't throw an assertion error and fail
the test

Resolve elastic#105556

server/src/test/java/org/elasticsearch/cluster/NodeConnectionsServiceTests.java

@@ -54,6 +54,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.BrokenBarrierException;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.CyclicBarrier;
 import java.util.concurrent.Semaphore;
@@ -266,7 +267,13 @@ public void onNodeDisconnected(DiscoveryNode node, Transport.Connection connecti
         // connection attempts to node0 block indefinitely
         final CyclicBarrier connectionBarrier = new CyclicBarrier(2);
         try {
-            nodeConnectionBlocks.put(node0, () -> connectionBarrier.await(10, TimeUnit.SECONDS));
+            nodeConnectionBlocks.put(node0, () -> {
+                try {
+                    connectionBarrier.await(10, TimeUnit.SECONDS);
+                } catch (BrokenBarrierException e) {
+                    logger.warn("Broken barrier", e);
+                }
+            });
             transportService.disconnectFromNode(node0);
 
             // can still connect to another node without blocking