fix(anthropic): replace retired model IDs in tests and docstrings (#35365)

## Summary

- Replace `claude-3-5-haiku-20241022` and `claude-3-7-sonnet-20250219`
with `claude-haiku-4-5-20251001` and `claude-sonnet-4-5-20250929`
respectively
- Both models were retired by Anthropic on February 19, 2026, causing
all anthropic integration tests to fail
- Updates integration tests, a unit test, and docstring examples in
`langchain-core`

See:
https://platform.claude.com/docs/en/docs/resources/model-deprecations

libs/core/langchain_core/callbacks/usage.py

@@ -24,7 +24,7 @@ class UsageMetadataCallbackHandler(BaseCallbackHandler):
         from langchain_core.callbacks import UsageMetadataCallbackHandler
 
         llm_1 = init_chat_model(model="openai:gpt-4o-mini")
-        llm_2 = init_chat_model(model="anthropic:claude-3-5-haiku-20241022")
+        llm_2 = init_chat_model(model="anthropic:claude-haiku-4-5-20251001")
 
         callback = UsageMetadataCallbackHandler()
         result_1 = llm_1.invoke("Hello", config={"callbacks": [callback]})
@@ -38,7 +38,7 @@ class UsageMetadataCallbackHandler(BaseCallbackHandler):
           'total_tokens': 18,
           'input_token_details': {'audio': 0, 'cache_read': 0},
           'output_token_details': {'audio': 0, 'reasoning': 0}},
-         'claude-3-5-haiku-20241022': {'input_tokens': 8,
+         'claude-haiku-4-5-20251001': {'input_tokens': 8,
           'output_tokens': 21,
           'total_tokens': 29,
           'input_token_details': {'cache_read': 0, 'cache_creation': 0}}}
@@ -110,7 +110,7 @@ def get_usage_metadata_callback(
         from langchain_core.callbacks import get_usage_metadata_callback
 
         llm_1 = init_chat_model(model="openai:gpt-4o-mini")
-        llm_2 = init_chat_model(model="anthropic:claude-3-5-haiku-20241022")
+        llm_2 = init_chat_model(model="anthropic:claude-haiku-4-5-20251001")
 
         with get_usage_metadata_callback() as cb:
             llm_1.invoke("Hello")
@@ -127,7 +127,7 @@ def get_usage_metadata_callback(
                 "input_token_details": {"audio": 0, "cache_read": 0},
                 "output_token_details": {"audio": 0, "reasoning": 0},
             },
-            "claude-3-5-haiku-20241022": {
+            "claude-haiku-4-5-20251001": {
                 "input_tokens": 8,
                 "output_tokens": 21,
                 "total_tokens": 29,

libs/partners/anthropic/tests/integration_tests/test_chat_models.py

@@ -35,7 +35,7 @@ from langchain_anthropic import ChatAnthropic
 from langchain_anthropic._compat import _convert_from_v1_to_anthropic
 from tests.unit_tests._utils import FakeCallbackHandler
 
-MODEL_NAME = "claude-3-5-haiku-20241022"
+MODEL_NAME = "claude-haiku-4-5-20251001"
 
 
 def test_stream() -> None:
@@ -454,7 +454,7 @@ async def test_astreaming() -> None:
 
 def test_tool_use() -> None:
     llm = ChatAnthropic(
-        model="claude-3-7-sonnet-20250219",  # type: ignore[call-arg]
+        model="claude-sonnet-4-5-20250929",  # type: ignore[call-arg]
         temperature=0,
     )
     tool_definition = {
@@ -487,7 +487,7 @@ def test_tool_use() -> None:
 
     # Test streaming
     llm = ChatAnthropic(
-        model="claude-3-7-sonnet-20250219",  # type: ignore[call-arg]
+        model="claude-sonnet-4-5-20250929",  # type: ignore[call-arg]
         temperature=0,
         # Add extra headers to also test token-efficient tools
         model_kwargs={

libs/partners/anthropic/tests/integration_tests/test_standard.py

@@ -12,7 +12,7 @@ from langchain_anthropic import ChatAnthropic
 
 REPO_ROOT_DIR = Path(__file__).parents[5]
 
-MODEL = "claude-3-5-haiku-20241022"
+MODEL = "claude-haiku-4-5-20251001"
 
 
 class TestAnthropicStandard(ChatModelIntegrationTests):

libs/partners/anthropic/tests/unit_tests/test_standard.py

@@ -48,7 +48,7 @@ def test_init_time_with_client(benchmark: BenchmarkFixture) -> None:
 
     def _init_in_loop_with_clients() -> None:
         for _ in range(10):
-            llm = ChatAnthropic(model="claude-3-5-haiku-20241022")
+            llm = ChatAnthropic(model="claude-haiku-4-5-20251001")
             _ = llm._client
             _ = llm._async_client