Take into account the next major version for the dropdown

This fixes the case where a new major version is the next version to be released, and the dropdown incorrectly shows a next patch version that doesn't exist.

I'm pretty sure we now have annual major versions, so .11 should be the last patch release, and we can change next month the last_major_patch to be 11. This time 13.12 was an exception.

The review app now shows 14.0-pre. You can also test this locally by changing the first online version in versions.yaml and see how it behaves.

Closes: #1023 (closed).