chore: Clean up stale secret references in CI workspace

## Summary

The shared CI workspace (ID: `19d7a891-8e0e-40ac-8a8c-5faf8d11e47c`) contains destinations with stale/deleted secret references. When the Airbyte Cloud API attempts to list these destinations, it returns a 500 error with the message:

```
Secret reference does not exist but is referenced in the config
```

## Impact

This causes intermittent CI failures in cloud integration tests that call `list_destinations` (directly or indirectly):
- `test_list_destinations` in `test_cloud_api_util.py`
- `test_deploy_destination` in `test_cloud_workspaces.py`

## Workaround

PR https://github.com/airbytehq/PyAirbyte/pull/885 adds targeted error handling to skip these tests when the stale secret reference error is encountered, rather than failing.

## Resolution

The proper fix is to clean up the stale destinations in the CI workspace:
1. Identify destinations with broken secret references
2. Either delete these destinations or update their configs with valid secret references

## Requested by

AJ Steers (@aaronsteers)

## Labels

- tech-debt
- ci