Fix library directory path for mingw

Use `sys.base_prefix` so that it works in venv

distutils/command/build_ext.py

@@ -225,7 +225,7 @@ def finalize_options(self):  # noqa: C901
                 # building third party extensions
                 self.library_dirs.append(
                     os.path.join(
-                        sys.prefix,
+                        sys.base_prefix,
                         "lib",
                         "python" + get_python_version(),
                         config_dir_name,