fix(unittest): add pymilvus and milvus-lite to unit dep group

This commit resolves unittest-3.12 issues.

- It adds pymilvus and milvus-lite to unit dep group
- It rename VectorDB to VectorStore

Signed-off-by: Mustafa Elbehery <melbeher@redhat.com>

pyproject.toml

@@ -123,6 +123,8 @@ unit = [
     "together",
     "coverage",
     "moto[s3]>=5.1.10",
+    "pymilvus>=2.6.1",
+    "milvus-lite>=2.5.0",
 ]
 # These are the core dependencies required for running integration tests. They are shared across all
 # providers. If a provider requires additional dependencies, please add them to your environment