Trying to sync metadata to a read-replica throws meaningless error

```SQL
select start_metadata_sync_to_node('localhost', 5505);
ERROR: you cannot sync metadata to a non-existent node
HINT: First, add the node with SELECT master_add_node('localhost',5505)
Time: 0.453 ms

table pg_dist_node;
nodeid | groupid | nodename | nodeport | noderack | hasmetadata | isactive | noderole | nodecluster | metadatasynced | shouldhaveshards
--------+---------+-----------+----------+----------+-------------+----------+-----------+-------------+----------------+------------------
2 | 1 | localhost | 5506 | default | f | t | secondary | cluster_c | f | t
3 | 1 | localhost | 5505 | default | f | t | secondary | cluster_b | f | t
1 | 1 | localhost | 5504 | default | t | t | primary | default | t | t
(3 rows)
```

We should probably use `FindWorkerNodeAnyCluster` instead of `FindWorkerNode`