Python: Bug: add_plugin_from_openapi() has hardcoded 5 seconds timeout

[GitAashishG]

When adding a plugin using add_plugin_from_openapi(), the timeout is hardcoded to 5-seconds.

This can be side-stepped by creating custom client for now:

            custom_client = httpx.AsyncClient(timeout=custom_timeout)

            # Create execution settings with the custom HTTP client
            execution_settings = OpenAPIFunctionExecutionParameters(
                http_client=custom_client
            )

            self.kernel.add_plugin_from_openapi(
                plugin_name=plugin_name,
                openapi_document_path=openapi_url,
                description=description,
                execution_settings=execution_settings,
     )