Refactor test files for improved readability and consistency

- Removed unnecessary blank lines and adjusted formatting in test files.
- Ensured consistent use of commas in function calls and assertions across various test cases.
- Updated import statements for better organization and clarity.
- Enhanced mock setups in tests for better isolation and reliability.
- Improved assertions to follow a consistent style for better readability.

tests/core/test_api_token_dependencies.py

@@ -49,7 +49,7 @@ class TestApiTokenDependencies:
 
         assert result == test_user
         mock_auth_service.get_user_by_api_token.assert_called_once_with(
-            "test_api_token_123"
+            "test_api_token_123",
         )
 
     @pytest.mark.asyncio
@@ -135,11 +135,11 @@ class TestApiTokenDependencies:
 
     @pytest.mark.asyncio
     async def test_get_current_user_api_token_service_exception(
-        self, mock_auth_service
+        self, mock_auth_service,
     ):
         """Test API token authentication with service exception."""
         mock_auth_service.get_user_by_api_token.side_effect = Exception(
-            "Database error"
+            "Database error",
         )
 
         api_token_header = "test_token"
@@ -170,7 +170,7 @@ class TestApiTokenDependencies:
 
         assert result == test_user
         mock_auth_service.get_user_by_api_token.assert_called_once_with(
-            "test_api_token_123"
+            "test_api_token_123",
         )
 
     @pytest.mark.asyncio
@@ -184,7 +184,7 @@ class TestApiTokenDependencies:
 
     @pytest.mark.asyncio
     async def test_api_token_no_expiry_never_expires(
-        self, mock_auth_service, test_user
+        self, mock_auth_service, test_user,
     ):
         """Test API token with no expiry date never expires."""
         test_user.api_token_expires_at = None