Remove Python 2 logic from functools (#13299)

Author: hauntsaninja

mypy/plugins/functools.py

@@ -22,10 +22,6 @@ def functools_total_ordering_maker_callback(
     ctx: mypy.plugin.ClassDefContext, auto_attribs_default: bool = False
 ) -> bool:
     """Add dunder methods to classes decorated with functools.total_ordering."""
-    if ctx.api.options.python_version < (3,):
-        # This plugin is not supported in Python 2 mode (it's a no-op).
-        return True
-
     comparison_methods = _analyze_class(ctx)
     if not comparison_methods:
         ctx.api.fail(