refactor: update flaky tests in test_schema.py (#3933)

* Fix flaky tests in `test_schema.py` by using sets for type comparisons

- Updated `post_process_type` function assertions to use sets for more reliable type comparisons.
- Adjusted imports for better code organization.

* Fix import order in test_database.py

* [autofix.ci] apply automated fixes

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Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

src/backend/tests/unit/test_database.py

@@ -2,7 +2,6 @@ import json
 from collections import namedtuple
 from uuid import UUID, uuid4
 
-from langflow.services.database.models.folder.model import FolderCreate
 import orjson
 import pytest
 from fastapi.testclient import TestClient
@@ -13,6 +12,7 @@ from langflow.graph.utils import log_transaction, log_vertex_build
 from langflow.initial_setup.setup import load_flows_from_directory, load_starter_projects
 from langflow.services.database.models.base import orjson_dumps
 from langflow.services.database.models.flow import Flow, FlowCreate, FlowUpdate
+from langflow.services.database.models.folder.model import FolderCreate
 from langflow.services.database.utils import session_getter
 from langflow.services.deps import get_db_service