protocol: add note about wl_buffer/wl_callback version
This is an exception which can be confusing. Add an explicit note about it in the protocol text.
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The migration is almost done, at least the rest should happen in the background. There are still a few technical difference between the old cluster and the new ones, and they are summarized in this issue. Please pay attention to the TL:DR at the end of the comment.
This is an exception which can be confusing. Add an explicit note about it in the protocol text.