CLN: remove Index.__inv__

closes #22335

Author: toobaz

pandas/core/indexes/base.py

@@ -4689,7 +4689,6 @@ def _add_numeric_methods_disabled(cls):
         cls.__neg__ = make_invalid_op('__neg__')
         cls.__pos__ = make_invalid_op('__pos__')
         cls.__abs__ = make_invalid_op('__abs__')
-        cls.__inv__ = make_invalid_op('__inv__')
 
     def _maybe_update_attributes(self, attrs):
         """ Update Index attributes (e.g. freq) depending on op """
@@ -4786,7 +4785,6 @@ def _evaluate_numeric_unary(self):
         cls.__neg__ = _make_evaluate_unary(operator.neg, '__neg__')
         cls.__pos__ = _make_evaluate_unary(operator.pos, '__pos__')
         cls.__abs__ = _make_evaluate_unary(np.abs, '__abs__')
-        cls.__inv__ = _make_evaluate_unary(lambda x: -x, '__inv__')
 
     @classmethod
     def _add_numeric_methods(cls):