revapi issues

[Volkan Yazıcı]

Mind somebody (@Ralph?) sharing what was wrong with revapi that we disabled
it in the 2.17.2 release, please? IIRC, we have upgraded the version,
adopted the new expected format in `revapi.json` files, yet this wasn't
enough. Further, we also have figured out some things weren't getting
properly checked at all before the upgrade. Right? Were there more?