fix: do not raise errors. Let mcp sdk handle the http errors

[wzxxing]

Summary

Changes

Please provide a summary of what's being changed

As a MCP proxy, we should not handle the HTTP transport error for the MCP SDK. Remove the raise_for_status call,

User experience

Please share what the user experience looks like before and after this change

No user experience should change after this change because the python mcp sdk already handles the errors by themselves.

> rg raise_for_status src/

src/mcp/client/streamable_http.py
211:                event_source.response.raise_for_status()
240:            event_source.response.raise_for_status()
278:            response.raise_for_status()

src/mcp/client/sse.py
66:                    event_source.response.raise_for_status()
131:                                    response.raise_for_status()

src/mcp/server/fastmcp/resources/types.py
160:            response.raise_for_status()

Fix bug for deleting session because the mcp sdk calls raise_for_status after some checking status code 404.

If we raise the error in the httpx event hooks, the error would make deleting session fail.

Checklist

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• I have reviewed the contributing guidelines
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented

Is this a breaking change? (Y/N)

• Yes
• No

Please add details about how this change was tested.

• Did integration tests succeed?
• If the feature is a new use case, is it necessary to add a new integration test case?

Acknowledgment

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