Recordsetitem nested update fails with KeyError because it has no version field #8725

Description

Updating a record set with an existing Recordsetitem inside recordsetitems fails with KeyError: 'version'.

update_or_create_resource assumes every nested item with an id has a version field. Recordsetitem has an id but no version column.

Steps to reproduce

1. Create a record set with two Collection Objects.
2. Get the record set and its item IDs:
   • GET /api/specify/recordset/{id}/
   • GET /api/specify/recordsetitem/?recordset={id}
3. Send an update with one existing item. The item has an id but no version:

{
  "version": 0,
  "recordsetitems": [
    {
      "id": 123,
      "recordid": 456
    }
  ]
}

PUT /api/specify/recordset/{id}/

4. The request returns 500:

{
  "exception": "KeyError",
  "message": "version"
}

Expected

A model without a version field should not be treated as versioned. The existing Recordsetitem should update without optimistic locking, or the API should return a clear error.

Notes

• Not reachable from the current UI. The UI adds and removes Recordsetitem rows one at a time.
• Found while adding record set unit tests in [test]: Unit tests for Record Sets #8714.