Resolve circular imports in runnables (#9675)

These are about to cause circular imports.

libs/langchain/langchain/schema/runnable/_locals.py

@@ -1,16 +1,27 @@
 from __future__ import annotations
 
-from typing import Any, AsyncIterator, Dict, Iterator, Mapping, Optional, Union
+from typing import (
-
+    TYPE_CHECKING,
-from langchain.callbacks.manager import (
+    Any,
-    AsyncCallbackManagerForChainRun,
+    AsyncIterator,
-    CallbackManagerForChainRun,
+    Dict,
+    Iterator,
+    Mapping,
+    Optional,
+    Union,
 )
+
 from langchain.load.serializable import Serializable
 from langchain.schema.runnable.base import Input, Output, Runnable
 from langchain.schema.runnable.config import RunnableConfig
 from langchain.schema.runnable.passthrough import RunnablePassthrough
 
+if TYPE_CHECKING:
+    from langchain.callbacks.manager import (
+        AsyncCallbackManagerForChainRun,
+        CallbackManagerForChainRun,
+    )
+
 
 class PutLocalVar(RunnablePassthrough):
     key: Union[str, Mapping[str, str]]

libs/langchain/langchain/schema/runnable/config.py

@@ -3,10 +3,11 @@ from __future__ import annotations
 from concurrent.futures import Executor, ThreadPoolExecutor
 from contextlib import contextmanager
 from copy import deepcopy
-from typing import Any, Dict, Generator, List, Optional, TypedDict
+from typing import TYPE_CHECKING, Any, Dict, Generator, List, Optional, TypedDict
 
-from langchain.callbacks.base import BaseCallbackManager, Callbacks
+if TYPE_CHECKING:
-from langchain.callbacks.manager import AsyncCallbackManager, CallbackManager
+    from langchain.callbacks.base import BaseCallbackManager, Callbacks
+    from langchain.callbacks.manager import AsyncCallbackManager, CallbackManager
 
 
 class RunnableConfig(TypedDict, total=False):
@@ -87,6 +88,8 @@ def patch_config(
 
 
 def get_callback_manager_for_config(config: RunnableConfig) -> CallbackManager:
+    from langchain.callbacks.manager import CallbackManager
+
     return CallbackManager.configure(
         inheritable_callbacks=config.get("callbacks"),
         inheritable_tags=config.get("tags"),
@@ -97,6 +100,8 @@ def get_callback_manager_for_config(config: RunnableConfig) -> CallbackManager:
 def get_async_callback_manager_for_config(
     config: RunnableConfig,
 ) -> AsyncCallbackManager:
+    from langchain.callbacks.manager import AsyncCallbackManager
+
     return AsyncCallbackManager.configure(
         inheritable_callbacks=config.get("callbacks"),
         inheritable_tags=config.get("tags"),