Views temp store should be cleared or not preserved when the views schema changes

This seems like a possible use case for a hook that runs every time after updates have run, but separate from hook_flush_caches(), like hook_after_updates_cleanup() or something like that?

That would solve the timing issue, but I think it would still be good to somehow figure out if something changed in Views data/schema before flushing the temp storage, but no idea how we could do that accurately.

Alternatively we could add config checking to saving Views, something like ✨ Provide a way to validate the current configuration state Needs work or what https://www.drupal.org/project/config_inspector → does and block saving a temp View when it's config isn't valid for the current schema versions

That would solve the timing issue, but I think it would still be good to somehow figure out if something changed in Views data/schema before flushing the temp storage

There is @joachim's idea to store a hash of views data in key/value or similar - but while that would work if we compared it on every cache clear, it won't work in a post-deploy hook, because then the hash would already have been updated and match views data before we get there (usually).