Fix WebSocketClient close: tolerate WS_SEND broken pipe error

[zhoushuo19]

Summary

When the server closes a WebSocket connection, calling .close() in curl_cffi >=0.11.1 raises a WS_SEND error with "Broken pipe".

This patch wraps .close() in a try/except block to suppress this specific non-critical error.

Traceback (most recent call last):
  File "/home/ec2-user/miniconda3/envs/hunter/lib/python3.11/site-packages/discord/gateway.py", line 172, in run
    await self.ws.close(4000)
  File "/home/ec2-user/miniconda3/envs/hunter/lib/python3.11/site-packages/discord/gateway.py", line 864, in close
    await self.socket.close(code, reason)
  File "/home/ec2-user/miniconda3/envs/hunter/lib/python3.11/site-packages/curl_cffi/requests/websockets.py", line 730, in close
    await self.send(msg, CurlWsFlag.CLOSE)
  File "/home/ec2-user/miniconda3/envs/hunter/lib/python3.11/site-packages/curl_cffi/requests/websockets.py", line 675, in send
    return await self.loop.run_in_executor(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/miniconda3/envs/hunter/lib/python3.11/concurrent/futures/thread.py", line 58, in run
    result = self.fn(*self.args, **self.kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/miniconda3/envs/hunter/lib/python3.11/site-packages/curl_cffi/curl.py", line 463, in ws_send
    self._check_error(ret, "WS_SEND")
  File "/home/ec2-user/miniconda3/envs/hunter/lib/python3.11/site-packages/curl_cffi/curl.py", line 154, in _check_error
    raise error
curl_cffi.curl.CurlError: Failed to WS_SEND, curl: (55) Send failure: Broken pipe. See https://curl.se/libcurl/c/libcurl-errors.html first for more details.

General Info

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• This PR fixes an issue (please put issue # in summary).
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, ...)