fix(lint): resolve ruff errors in tests and run_tests.py

- Fix import sorting (I001)
- Remove unused imports and variables (F401, F841)
- Add noqa for test code (S106 hardcoded passwords, S314 XML parsing)
- Auto-format with ruff format

tests/apps/core/test_bulk_operations.py

@@ -71,6 +71,7 @@ class BulkOperationsIntegrationTest(TestCase):
 
     def test_bulk_create_chunked(self):
         """Тест массового создания чанками."""
+
         # Создаём тестовый сервис с BulkOperationsMixin
         class TestService(BulkOperationsMixin):
             model = BackgroundJob
@@ -88,10 +89,13 @@ class BulkOperationsIntegrationTest(TestCase):
         self.assertEqual(count, 10)
 
         # Проверяем что все созданы
-        self.assertEqual(BackgroundJob.objects.filter(task_name="test.bulk.task").count(), 10)
+        self.assertEqual(
+            BackgroundJob.objects.filter(task_name="test.bulk.task").count(), 10
+        )
 
     def test_bulk_delete(self):
         """Тест массового удаления."""
+
         class TestService(BulkOperationsMixin):
             model = BackgroundJob
 
@@ -109,10 +113,13 @@ class BulkOperationsIntegrationTest(TestCase):
         deleted = TestService.bulk_delete(ids_to_delete)
 
         self.assertEqual(deleted, 3)
-        self.assertEqual(BackgroundJob.objects.filter(task_name="test.delete.task").count(), 2)
+        self.assertEqual(
+            BackgroundJob.objects.filter(task_name="test.delete.task").count(), 2
+        )
 
     def test_bulk_update_fields(self):
         """Тест массового обновления полей."""
+
         class TestService(BulkOperationsMixin):
             model = BackgroundJob
 
@@ -138,6 +145,7 @@ class BulkOperationsIntegrationTest(TestCase):
 
     def test_bulk_update_or_create_creates(self):
         """Тест upsert - создание новых."""
+
         class TestService(BulkOperationsMixin):
             model = BackgroundJob
 
@@ -157,6 +165,7 @@ class BulkOperationsIntegrationTest(TestCase):
 
     def test_bulk_update_or_create_updates(self):
         """Тест upsert - обновление существующих."""
+
         class TestService(BulkOperationsMixin):
             model = BackgroundJob