Obfuscate Bearer Token values in logs (#16164)
Sometimes a credential's `Debug` formatted value appears in tracing logs
- make sure the credential doesn't appear there.
## Test plan
Added a test case + ran
```
uv pip install --default-index $PYX_API_URL/$SOME_INDEX $SOME_PACKAGE -vv
```
With an authenticated uv client and confirmed the tokens are obfuscated.
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Co-authored-by: Zsolt Dollenstein <zsol.zsol@gmail.com>
