Repository: langchain
Issue: importing hub fails with latest(0.3.9) version
Labels: 🤖:bug,investigate

### Checked other resources

- [X] I added a very descriptive title to this issue.
- [X] I searched the LangChain documentation with the integrated search.
- [X] I used the GitHub search to find a similar question and didn't find it.
- [X] I am sure that this is a bug in LangChain rather than my code.
- [X] The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).

### Example Code

The following code:

```python
from langchain import hub
```

### Error Message and Stack Trace (if applicable)

```
% uv run scripts/script.py 
Traceback (most recent call last):
  File "/path/scripts/script.py", line 5, in <module>
    from langchain import hub
  File "/path/.venv/lib/python3.11/site-packages/langchain/__init__.py", line 8, in <module>
    from langchain.agents import MRKLChain, ReActChain, SelfAskWithSearchChain
  File "/path/.venv/lib/python3.11/site-packages/langchain/agents/__init__.py", line 2, in <module>
    from langchain.agents.agent import Agent
  File "/path/.venv/lib/python3.11/site-packages/langchain/agents/agent.py", line 10, in <module>
    from langchain.chains.base import Chain
  File "/path/.venv/lib/python3.11/site-packages/langchain/chains/__init__.py", line 2, in <module>
    from langchain.chains.conversation.base import ConversationChain
  File "/path/.venv/lib/python3.11/site-packages/langchain/chains/conversation/base.py", line 7, in <module>
    from langchain.chains.conversation.memory import ConversationBufferMemory
  File "/path/.venv/lib/python3.11/site-packages/langchain/chains/conversation/memory.py", line 7, in <module>
    from langchain.chains.conversation.prompt import SUMMARY_PROMPT
  File "/path/.venv/lib/python3.11/site-packages/langchain/chains/conversation/prompt.py", line 2, in <module>
    from langchain.prompts.prompt import PromptTemplate
  File "/path/.venv/lib/python3.11/site-packages/langchain/prompts/__init__.py", line 2, in <module>
    from langchain.prompts.base import BasePromptTemplate
  File "/path/.venv/lib/python3.11/site-packages/langchain/prompts/base.py", line 35, in <module>
    class BasePromptTemplate(BaseModel, ABC):
  File "/path/.venv/lib/python3.11/site-packages/langchain/prompts/base.py", line 41, in BasePromptTemplate
    @root_validator()
     ^^^^^^^^^^^^^^^^
  File "/path/.venv/lib/python3.11/site-packages/pydantic/deprecated/class_validators.py", line 240, in root_validator
    raise PydanticUserError(
pydantic.errors.PydanticUserError: If you use `@root_validator` with pre=False (the default) you MUST specify `skip_on_failure=True`. Note that `@root_validator` is deprecated and should be replaced with `@model_validator`.

For further information visit https://errors.pydantic.dev/2.10/u/root-validator-pre-skip
```

### Description

I try to use hub for pulling my prompts.
it worked with version 0.3.7 but when I use 0.3.9, above error occurs and it fails for just importing

### System Info

System Information
------------------
> OS:  Darwin
> OS Version:  Darwin Kernel Version 23.4.0: Fri Mar 15 00:12:49 PDT 2024; root:xnu-10063.101.17~1/RELEASE_ARM64_T6020
> Python Version:  3.11.4 (v3.11.4:d2340ef257, Jun  6 2023, 19:15:51) [Clang 13.0.0 (clang-1300.0.29.30)]

Package Information
-------------------
> langchain_core: 0.3.21
> langchain: 0.3.7
> langsmith: 0.1.147
> langchain_openai: 0.2.10
> langchain_text_splitters: 0.3.2

Optional packages not installed
-------------------------------
> langserve

Other Dependencies
------------------
> aiohttp: 3.11.8
> async-timeout: Installed. No version info available.
> httpx: 0.28.0
> jsonpatch: 1.33
> langsmith-pyo3: Installed. No version info available.
> numpy: 1.26.4
> openai: 1.55.3
> orjson: 3.10.12
> packaging: 24.2
> pydantic: 2.10.2
> PyYAML: 6.0.2
> requests: 2.32.3
> requests-toolbelt: 1.0.0
> SQLAlchemy: 2.0.36
> tenacity: 9.0.0
> tiktoken: 0.8.0
> typing-extensions: 4.12.2