Optimize string concatenation in getNodeDescription() (#3262)

Replace String.join with Collectors.joining to avoid intermediate collection creation,
improving performance by eliminating the unnecessary List creation step.

Author: ori0o0p

src/main/java/io/lettuce/core/cluster/NodeSelectionInvocationHandler.java

@@ -264,7 +264,7 @@ private RedisCommandExecutionException createExecutionException(Map<RedisCluster
     }
 
     private String getNodeDescription(List<RedisClusterNode> notFinished) {
-        return String.join(", ", notFinished.stream().map(this::getDescriptor).collect(Collectors.toList()));
+        return notFinished.stream().map(this::getDescriptor).collect(Collectors.joining(", "));
     }
 
     private String getDescriptor(RedisClusterNode redisClusterNode) {