Rebuttal Stage: Expire invitations that are not being used

[melisabok]

If a venue select in the RebuttalStage "Multiple author rebuttals per paper" and then change it to "One author rebuttal per posted review". The process function creates different invitation ids.

We should expire the previous invitations and create the new ones.

How to reproduce this issue?:

• Set the rebuttal stage for a venue selecting "Multiple author rebuttals per paper"
• This creates invitation like venue.cc/Submission1/-/Rebuttal
• Change the rebuttal stage for the same venue selecting "One author rebuttal per posted review"
• This created the invitation like venue.cc/Submission1/Review1/-/Rebuttal

So both invitations are active, we should expire the previous. @celestemartinez I think there is something done in the edit process function that expire invitations but it doesn't contemplate this caae, should we add the fix there?

[celestemartinez]

We can make this change. Neuirps did use 2 rebuttal stages at some point:

• Neurips 2023 used both an Author_Rebuttal invitation (one per paper) and a Rebuttal invitation .

However, we don't allow changing the name of the Rebuttal Stage from the request form, so perhaps we only should allow one being run from the UI. For Neurips, it looks like the Author_Rebuttal was run from python.

[melisabok]

I would use two different stages if they want to allow both options.