core: Cache RunnableLambda deps (#29200)

`RunnableLambda`'s `deps` may do costly OS operation by calling
`get_function_nonlocals`.
So it's better to cache it.
See #29043

libs/core/langchain_core/runnables/base.py

@@ -4457,7 +4457,7 @@ class RunnableLambda(Runnable[Input, Output]):
             module_name=module,
         )
 
-    @property
+    @functools.cached_property
     def deps(self) -> list[Runnable]:
         """The dependencies of this Runnable.