SIENTIAPDE-1646

Update dependencies and refactor MLFlow activities

- Replaced direct GitHub dependencies in `requirements.txt` with specific versioned packages for `sientia_do` and `sientia_model`.
- Refactored imports in `activities.py` to streamline the code structure.
- Enhanced the `MLFlow` class in `mlflow.py` by introducing a method to resolve model aliases, improving flexibility in model lookups.
- Simplified shutdown logic in `worker.py` for better readability.
- Added new tests for MLFlow activities and improved existing test coverage for data handling and model retraining processes.

laborious/worker/worker.py

@@ -264,10 +264,8 @@ async def main():
         logger.custom_error(f'An unhandled exception occurred: {e}', metadata)
         exit_code = 1
     finally:
-        if notification_handler:
-            notification_handler.shutdown()
-        if activities:
-            await activities.shutdown()
+        notification_handler.shutdown()
+        await activities.shutdown()
         metrics.APP_UP.labels(pod_id=POD_ID).set(0)  # Mark app as DOWN
         sys.exit(exit_code)