[API-Compat] Updated ForbidKeywordsDecorator

Author: Enigmatisms

python/paddle/utils/decorator_utils.py

@@ -114,16 +114,14 @@ def process(
 
         return args, kwargs
 
-class ForbidKeywordsDecorator(DecoratorBase[_P, _R]):
+class ForbidKeywordsDecorator(DecoratorBase):
     """A decorator that hints users to use the correct `compat` functions, when erroneous keyword arguments are detected"""
 
     def __init__(
-        self, illegal_keys: list[str] | str, func_name: str, correct_name: str
+        self, illegal_keys: list[str], func_name: str, correct_name: str
     ) -> None:
         super().__init__()
-        self.illegal_keys = (
-            [illegal_keys] if isinstance(illegal_keys, str) else illegal_keys
-        )
+        self.illegal_keys = illegal_keys
         self.func_name = func_name
         self.correct_name = correct_name