Refactor tests for async compatibility and enhance IngestorManager functionality
- Updated test cases in `test_app.py`, `test_ingestor.py`, and `test_ingestor_manager.py` to use async/await syntax for improved concurrency.
- Refactored methods in IngestorManager and related classes to support asynchronous operations, ensuring non-blocking behavior during execution.
- Enhanced mock setups in tests to accommodate async methods, improving test reliability and performance.
