Update poetry.lock and enhance test_milvus.py

- Upgraded Poetry version from 2.1.1 to 2.1.2 in poetry.lock.
- Added new packages: grpcio (1.67.1), milvus-lite (2.4.12), numpy (2.2.5), pandas (2.2.3), pymilvus (2.5.7), pytz (2025.2), setuptools (79.0.0), tzdata (2025.2), and ujson (5.10.0) with their respective dependencies.
- Modified test_milvus.py to improve metadata handling and added dialog index for analysis functions in sample_vcon.
- Enhanced the test_save function to ensure proper mock setup and verification of Milvus operations.

Author: howethomas