Update project configuration and dependencies

- Added `.vscode` to `.gitignore` to exclude Visual Studio Code settings.
- Updated `pyproject.toml` to include `ruff` for linting and configured its settings.
- Modified `uv.lock` to include `ruff` in both optional and development dependencies.
- Refactored type hints in several files to use `str | None` for optional parameters.
- Cleaned up unused imports and whitespace in various modules for improved code clarity.

tests/test_models.py

@@ -1,8 +1,8 @@
 import json
 
 import pytest
-
 from conftest import FIXTURES, load
+
 from oxi.interfaces import device_registry
 
 MODEL_CASES = [

tests/test_network.py

@@ -1,7 +1,7 @@
 import pytest
 import responses
-
 from conftest import load
+
 from oxi import OxiAPI
 from oxi.exception import OxiAPIError
 
@@ -84,4 +84,4 @@ def test_unknown_model_raises_value_error():
 
     api = OxiAPI(url=BASE)
     with pytest.raises(ValueError, match="not found in registry"):
-        api.node("HQ").config
+        _ = api.node("HQ").config

tests/test_units.py

@@ -1,10 +1,9 @@
 import pytest
-
 from conftest import load
+
 from oxi.exception import OxiAPIError
 from oxi.interfaces import device_registry
 from oxi.interfaces.base import BaseDevice
-from oxi.interfaces.contract import Interfaces, System
 from oxi.interfaces.utils import decode_utf, expand_vlan_range