Enforce ruff/refurb rule FURB118

FURB118 Use `operator.itemgetter(0)` instead of defining a lambda

setuptools/command/build_ext.py

@@ -319,7 +319,7 @@ def get_outputs(self) -> list[str]:
     def get_output_mapping(self) -> dict[str, str]:
         """See :class:`setuptools.commands.build.SubCommand`"""
         mapping = self._get_output_mapping()
-        return dict(sorted(mapping, key=lambda x: x[0]))
+        return dict(sorted(mapping, key=operator.itemgetter(0)))
 
     def __get_stubs_outputs(self):
         # assemble the base name for each extension that needs a stub

setuptools/command/build_py.py

@@ -153,7 +153,7 @@ def get_output_mapping(self) -> dict[str, str]:
             self._get_package_data_output_mapping(),
             self._get_module_mapping(),
         )
-        return dict(sorted(mapping, key=lambda x: x[0]))
+        return dict(sorted(mapping, key=operator.itemgetter(0)))
 
     def _get_module_mapping(self) -> Iterator[tuple[str, str]]:
         """Iterate over all modules producing (dest, src) pairs."""

setuptools/command/editable_wheel.py

@@ -865,7 +865,7 @@ def _finder_template(
     """Create a string containing the code for the``MetaPathFinder`` and
     ``PathEntryFinder``.
     """
-    mapping = dict(sorted(mapping.items(), key=lambda p: p[0]))
+    mapping = dict(sorted(mapping.items(), key=operator.itemgetter(0)))
     return _FINDER_TEMPLATE.format(name=name, mapping=mapping, namespaces=namespaces)