Fix Lime pyre fixme issues

Summary: Fixing unresolved pyre fixme issues in corresponding file

Differential Revision: D76736867

Author: Vivek Miglani

captum/attr/_core/lime.py

@@ -548,8 +548,7 @@ def generate_perturbation() -> (
 
         return generate_perturbation
 
-    # pyre-fixme[24] Generic type `Callable` expects 2 type parameters.
-    def attribute_future(self) -> Callable:
+    def attribute_future(self) -> None:
         r"""
         This method is not implemented for LimeBase.
         """
@@ -1116,8 +1115,7 @@ def attribute(  # type: ignore
             show_progress=show_progress,
         )
 
-    # pyre-fixme[24] Generic type `Callable` expects 2 type parameters.
-    def attribute_future(self) -> Callable:
+    def attribute_future(self) -> None:
         return super().attribute_future()
 
     def _attribute_kwargs(  # type: ignore

tests/attr/test_lime.py

@@ -482,7 +482,7 @@ def test_futures_not_implemented(self) -> None:
         )
         attributions = None
         with self.assertRaises(NotImplementedError):
-            attributions = lime.attribute_future()
+            attributions = lime.attribute_future()  # type: ignore
         self.assertEqual(attributions, None)
 
     # pyre-fixme[24]: Generic type `Callable` expects 2 type parameters.