"rosa whoami --output json" errors are not json

When I don't have a valid `rosa` token, I would expect `--output json` to give me an error _in JSON_, rather than printing non-JSON output

```
rosa whoami --output json
E: Failed to create OCM connection: error creating connection. Not able to get authentication token: access and refresh tokens are unavailable or expired, and there are no password or client secret to request new ones
```