fix: remove delay when using csv export actions. The CSV file is written incrementally, so we can't determine the Content-Length. When using HTTP/1.1, this causes a delay while the browser waits for a timeout. Forcing the connection to close after the CSV file is written removes the delay. Ideally we should shift to chunked transfer encoding for these two actions, but that is much more invasive and when posting a request for CSV, it is unlikely that another request will be sent over the same socket.

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