"Download All Responses" button and API endpoint for retrieving guestbook responses time out when used to get responses from certain collections

What steps does it take to reproduce the issue?

• When does this issue occur?
  When trying to get all guestbook responses for a collection by:

  • Going to the collection's "Manage Dataset Guestbooks" page and clicking "Download All Responses"
  • Using the Retrieve Guestbook Responses for a Dataverse Collection API endpoint described at https://guides.dataverse.org/en/6.9/api/native-api.html#retrieve-guestbook-responses-for-a-dataverse-collection

• Which page(s) does it occurs on?

  • On the "Manage Dataset Guestbooks" pages of certain collections in Harvard Dataverse
  • In terminals and IDE's and where ever else users might use the API endpoint to get guestbook responses of certain collections in Harvard Dataverse

• What happens?

  • After clicking "Download All Responses" and waiting for a bit, a "504 Gateway Time-out" page appears

  • After trying to use the API endpoint and waiting for a bit, the endpoint returns "504 Gateway Time-out"
    Endpoint runs for about a minute...
    

    ... and times out
    

  Sometimes users are able to get the responses, using the "Download All Responses" button or the API endpoint, after a few tries.

• To whom does it occur (all users, curators, superusers)?
  Superusers and managers of collections

• What did you expect to happen?

  • The guestbook always downloads as a CSV file, at least for collections with fewer file downloads
  • The "Retrieve Guestbook Responses for a Dataverse Collection endpoint" always returns the guestbook responses instead of a 504 timeout error, even for guestbooks with many file downloads. We created this endpoint for cases where users can't view or download their guestbook respones using their browsers because there are too many responses. See IQSS/dataverse #7767

Which version of Dataverse are you using?
v6.9 - v6.11

Any related open or closed issues to this bug report?

• https://github.com/IQSS/dataverse/issues/7767