Fix Windows CI: Add create=True to os.getloadavg patch

- Use create=True parameter to allow patching non-existent attributes
- Fixes Windows test failures where os.getloadavg doesn't exist
- Mock creates the attribute instead of failing to find original
- Should now work across all platforms

Author: dknell

tests/conftest.py

@@ -11,7 +11,7 @@ def mock_windows_specific_functions():
     """Mock Windows-incompatible functions for all tests."""
     # Only apply this mock on Windows or if getloadavg doesn't exist
     if not hasattr(os, 'getloadavg'):
-        with patch('system_info_mcp.tools.os.getloadavg', return_value=(0.1, 0.1, 0.1)):
+        with patch('system_info_mcp.tools.os.getloadavg', return_value=(0.1, 0.1, 0.1), create=True):
             yield
     else:
         yield