fix(tests): remove chroma and qdrant from vector io unit tests (#3759)

These vector databases are already thoroughly tested in integration
tests.
Unit tests now focus on sqlite_vec, faiss, and pgvector with mocked
dependencies, removing the need for external service dependencies.

## Changes:
- Deleted test_qdrant.py unit test file
- Removed chroma/qdrant fixtures and parametrization from conftest.py
- Fixed SqliteKVStoreConfig import to use correct location
- Removed chromadb, qdrant-client, pymilvus, milvus-lite, and
  weaviate-client from unit test dependencies in pyproject.toml

pyproject.toml

@@ -87,19 +87,14 @@ unit = [
     "pypdf",
     "mcp",
     "chardet",
-    "qdrant-client",
     "sqlalchemy",
     "sqlalchemy[asyncio]>=2.0.41",
     "blobfile",
     "faiss-cpu",
-    "pymilvus>=2.6.1",
-    "milvus-lite>=2.5.0",
     "litellm",
     "together",
     "coverage",
-    "chromadb>=1.0.15",
     "moto[s3]>=5.1.10",
-    "weaviate-client>=4.16.4",
 ]
 # 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
@@ -120,6 +115,8 @@ test = [
     "sqlalchemy",
     "sqlalchemy[asyncio]>=2.0.41",
     "requests",
+    "chromadb>=1.0.15",
+    "qdrant-client",
     "pymilvus>=2.6.1",
     "milvus-lite>=2.5.0",
     "weaviate-client>=4.16.4",