[misc] fix typing (#11540)

Signed-off-by: youkaichao <youkaichao@gmail.com>

vllm/compilation/backends.py

@@ -208,8 +208,8 @@ def wrap_inductor(graph: fx.GraphModule,
         from torch._inductor.compile_fx import graph_returns_tuple
         returns_tuple = graph_returns_tuple(graph)
 
-        # this is the graph we return to Dynamo to run
-        def compiled_graph(*args) -> Optional[fx.CompiledFxGraph]:
+        # this is the callable we return to Dynamo to run
+        def compiled_graph(*args):
             # convert args to list
             list_args = list(args)
             graph_output = inductor_compiled_graph(list_args)
@@ -537,7 +537,8 @@ class VllmBackend:
             example_inputs[x].clone() for x in self.sym_tensor_indices
         ]
 
-        def copy_and_call(*args) -> fx.GraphModule:
+        # this is the callable we return to Dynamo to run
+        def copy_and_call(*args):
             list_args = list(args)
             for i, index in enumerate(self.sym_tensor_indices):
                 runtime_tensor = list_args[index]