The AppID auth backend is removed in Vault 1.12 and prevents the process
from starting. We now enable the legacy tests conditionally depending on
the actual Vault version.
In preparations for 1.0 compatibility and some later features the test
data generated with 0.5 becomes more of a problem without intermediate
updates, so it is now rebuilt from scratch.
As part of this change the unseal key is now split in 3 parts with a
threshold of 2 instead of the former 1/1,
