Changes have been made based on the feedback

Author: uko3211

mypy/nodes.py

@@ -800,7 +800,6 @@ class FuncDef(FuncItem, SymbolNode, Statement):
         "dataclass_transform_spec",
         "docstring",
         "deprecated",
-        "plugin_generated",
     )
 
     __match_args__ = ("name", "arguments", "type", "body")
@@ -813,7 +812,6 @@ def __init__(
         body: Block | None = None,
         typ: mypy.types.FunctionLike | None = None,
         type_args: list[TypeParam] | None = None,
-        plugin_generated: bool | None = None,
     ) -> None:
         super().__init__(arguments, body, typ, type_args)
         self._name = name
@@ -834,7 +832,6 @@ def __init__(
         # the majority). In cases where self is not annotated and there are no Self
         # in the signature we can simply drop the first argument.
         self.is_trivial_self = False
-        self.plugin_generated = False
 
     @property
     def name(self) -> str:

mypy/plugins/attrs.py

@@ -1034,7 +1034,8 @@ def _get_attrs_init_type(typ: Instance) -> CallableType | None | AnyType:
         return None
     # case 1: normal FuncDef
     if isinstance(init_method, FuncDef) and isinstance(init_method.type, CallableType):
-        if init_method.plugin_generated:
+        init_node = typ.type.get("__init__") or typ.type.get(ATTRS_INIT_NAME)
+        if init_node.plugin_generated:
             return init_method.type
         else:
             return AnyType(TypeOfAny.special_form)