I have confirmed that this problem was fixed upstream in LV2. It's a
problem with the current release (1.16).

The tests pass when I build lv2 with this patch (not released yet).
https://gitlab.com/lv2/lv2/-/commit/2dd45ffd8d19491407bc9f9e0b395fbdefaaacf0

We could just wait until the next release, but I would temporarily
disable the tests to prevent broken installations/upgrades.