A mcp_server_tools error with StdioServerParams by using excel-mcp-server

### What happened?

**Describe the bug**
I got 

> json_schema_to_pydantic.exceptions.TypeError: Array type must specify 'items' schema

and

> ValueError: I/O operation on closed pipe

when using mcp_server_tools()

**To Reproduce**
Steps to reproduce the behavior. Please include code and outputs such as stacktrace.

I pulled the @negokaz/excel-mcp-server and try to build an agent for test.
`npm install -g @negokaz/excel-mcp-server`
First I build in VSCode with Cline for testing, and it works with this quest:

> Create a excel file called test_with_autogen.xlsx with some content, and save in Desktop folder

My os is Windows 11, so my configuration is 
```
{
    "mcpServers": {
        "excel": {
            "command": "cmd",
            "args": ["/c", "npx", "--yes", "@negokaz/excel-mcp-server"],
            "env": {
                "EXCEL_MCP_PAGING_CELLS_LIMIT": "4000"
            }
        }
    }
}
```

Second, when I build the same excel-mcp-server in Autogen with MCP, the code is 

```
import asyncio
from autogen_ext.models.openai import OpenAIChatCompletionClient
from autogen_ext.tools.mcp import StdioServerParams, mcp_server_tools
from autogen_agentchat.agents import AssistantAgent
from autogen_core import CancellationToken
from autogen_agentchat.messages import TextMessage
from autogen_agentchat.ui import Console

async def main_excel() -> None:
    server_params = StdioServerParams(
        command="cmd",
        args=["/c", "npx", "--yes", "@negokaz/excel-mcp-server"],
        env={
            "EXCEL_MCP_PAGING_CELLS_LIMIT": "4000"
            }
    )

    # Get all available tools from the server
    tools = await mcp_server_tools(server_params)

    # Create an agent that can use all the tools
    model_client_OpenAI = \
        OpenAIChatCompletionClient(model="gpt-3.5-turbo",base_url="https://xxxxxxx",api_key="xxxxxxxx")

    agent = AssistantAgent(
        name="excel",
        model_client=model_client_OpenAI,
        tools=tools,  # type: ignore
    )


    # The agent can now use any of the filesystem tools
    await agent.run(task="Create a excel file called test_with_autogen.xlsx with some content, and save in Desktop folder", cancellation_token=CancellationToken())


if __name__ == "__main__":
    asyncio.run(main_excel())
```

It got the error:

> Traceback (most recent call last):
>   File "E:\Work\AI\APEXBOT\autogen_mcp_1.py", line 71, in <module>
>     asyncio.run(main_excel())
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\runners.py", line 194, in run
>     return runner.run(main)
>            ^^^^^^^^^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\runners.py", line 118, in run
>     return self._loop.run_until_complete(task)
>            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\base_events.py", line 687, in run_until_complete
>     return future.result()
>            ^^^^^^^^^^^^^^^
>   File "E:\Work\AI\APEXBOT\autogen_mcp_1.py", line 53, in main_excel
>     tools = await mcp_server_tools(server_params)
>             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\site-packages\autogen_ext\tools\mcp\_factory.py", line 139, in mcp_server_tools
>     return [StdioMcpToolAdapter(server_params=server_params, tool=tool) for tool in tools.tools]
>             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\site-packages\autogen_ext\tools\mcp\_stdio.py", line 48, in __init__
>     super().__init__(server_params=server_params, tool=tool)
>   File "C:\Users\Omar\anaconda3\Lib\site-packages\autogen_ext\tools\mcp\_base.py", line 38, in __init__
>     input_model = create_model(tool.inputSchema)
>                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\site-packages\json_schema_to_pydantic\__init__.py", line 42, in create_model
>     return builder.create_pydantic_model(schema, root_schema)
>            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\site-packages\json_schema_to_pydantic\model_builder.py", line 62, in create_pydantic_model
>     field_type = self._get_field_type(field_schema, root_schema)
>                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\site-packages\json_schema_to_pydantic\model_builder.py", line 98, in _get_field_type
>     return self.type_resolver.resolve_type(field_schema, root_schema)
>            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\site-packages\json_schema_to_pydantic\resolvers.py", line 52, in resolve_type
>     raise TypeError("Array type must specify 'items' schema")
> json_schema_to_pydantic.exceptions.TypeError: Array type must specify 'items' schema
> Exception ignored in: <function BaseSubprocessTransport.__del__ at 0x000002353D51DDA0>
> Traceback (most recent call last):
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\base_subprocess.py", line 126, in __del__
>     self.close()
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\base_subprocess.py", line 104, in close
>     proto.pipe.close()
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\proactor_events.py", line 109, in close
>     self._loop.call_soon(self._call_connection_lost, None)
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\base_events.py", line 795, in call_soon
>     self._check_closed()
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\base_events.py", line 541, in _check_closed
>     raise RuntimeError('Event loop is closed')
> RuntimeError: Event loop is closed
> Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x000002353D51F560>
> Traceback (most recent call last):
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\proactor_events.py", line 116, in __del__
>     _warn(f"unclosed transport {self!r}", ResourceWarning, source=self)
>                                ^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\proactor_events.py", line 80, in __repr__
>     info.append(f'fd={self._sock.fileno()}')
>                       ^^^^^^^^^^^^^^^^^^^
>   File "C:\Users\Omar\anaconda3\Lib\asyncio\windows_utils.py", line 102, in fileno
>     raise ValueError("I/O operation on closed pipe")
> ValueError: I/O operation on closed pipe
> 


**Expected behavior**
I think it has to do the same work like "VSCode + Cline", but it got errors.

**Additional context**
I'd build the @modelcontextprotocol\\server-filesystem in Autogen, and it works. So I just want to build more MCP application for testing, like excel, but I met some problem.



### Which packages was the bug in?

Python Extensions (autogen-ext)

### AutoGen library version.

Python 0.4.7

### Other library version.

_No response_

### Model used

gpt-3.5-turbo

### Model provider

OpenAI

### Other model provider

_No response_

### Python version

3.12

### .NET version

None

### Operating system

Windows

Labels: needs-triage
State: closed