Revert "Fix PEP487 __set_name__ protocol in BaseModel (#4407)" (#4411)

This reverts commit d501c39.

pydantic/main.py

@@ -286,12 +286,6 @@ def is_untouched(v: Any) -> bool:
         if resolve_forward_refs:
             cls.__try_update_forward_refs__()
 
-        # preserve `__set_name__` protocol defined in https://peps.python.org/pep-0487
-        for name, obj in namespace.items():
-            set_name = getattr(obj, '__set_name__', None)
-            if callable(set_name):
-                set_name(cls, name)
-
         return cls
 
     def __instancecheck__(self, instance: Any) -> bool:

tests/test_create_model.py

@@ -3,7 +3,6 @@
 import pytest
 
 from pydantic import BaseModel, Extra, Field, ValidationError, create_model, errors, validator
-from pydantic.fields import ModelPrivateAttr
 from pydantic.generics import GenericModel
 
 
@@ -223,22 +222,3 @@ class TestGenericModel(GenericModel):
     result = AAModel[int](aa=1)
     assert result.aa == 1
     assert result.__config__.orm_mode is True
-
-
-def test_set_name():
-    calls = []
-
-    class class_deco(ModelPrivateAttr):
-        def __init__(self, fn):
-            super().__init__()
-            self.fn = fn
-
-        def __set_name__(self, owner, name):
-            calls.append((owner, name))
-
-    class A(BaseModel):
-        @class_deco
-        def _some_func(self):
-            return self
-
-    assert calls == [(A, '_some_func')]