test(docstore): enhance test_add_documents with dynamic `docstore_c…

…lass` parameter

- Introduce `docstore_class` parameter to `test_add_documents` function to increase test flexibility and facilitate testing with different document store implementations.
- Replace direct call to `delete_collection` with `docstore.reset()` for cleanup, aligning with best practices for test isolation and teardown.

tests/components/test_docstore.py

@@ -12,7 +12,7 @@ def test_document_store():
     docstore.client.delete_collection("test_collection")
 
 
-def test_add_documents(tmp_path: Path):
+def test_add_documents(tmp_path: Path, docstore_class):
     """Test the add_documents method of DocumentStore."""
     # Create a temporary collection for testing
     collection_name = "test_collection"
@@ -51,4 +51,4 @@ def test_add_documents(tmp_path: Path):
     )
 
     # Clean up the temporary collection
-    docstore.client.delete_collection(collection_name)
+    docstore.reset()