wkg 0.15.0 wit fetch reports warning, but the fetch succeed

As pasted below, it reported warning. I though it failed so spend like an hour to figure out why. :') But it seems these warnings are useless? The fetch actually succeeded.

```bash
❯ wkg wit fetch
2026-03-18T08:01:51.995535Z WARN oci_client::token_cache: Invalid bearer token error=Error(InvalidToken)
2026-03-18T08:01:52.747776Z WARN oci_client::token_cache: Invalid bearer token error=Error(InvalidToken)
```

```bash
wkg --version
wkg 0.15.0
```