[Pulsar-Admin] Ledgers in the partitioned-stats-internal command are missing

**Describe the bug**

Run the command:

```
bin/pulsar-admin topics partitioned-stats-internal xxxx
```

the input as follows:


And run the command again, we can get the ledgers

Start by reproducing the issue with `bin/pulsar-admin topics partitioned-stats-internal xxxx` and compare repeated results. Locate the command's entry point and trace how partitioned statistics are assembled and ledgers are returned. Done means the command consistently includes the ledgers shown by the follow-up invocation, with regression coverage for the behavior.

Written by the indexing model from the issue text.