Request expertise: aletrnate group expertise

[celestemartinez]

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When we request expertise between two groups, we add the first group's expertise invitaton as the seond group's expertise invitation. https://github.com/openreview/openreview-py/blob/d5f1f8caeb87a68ad52f4aeea038de890635abd0/openreview/api/client.py#L2175C39-L2176C51

We need to make sure we add the correct expertise invitation to entityB when entityB is a group.