Unfortunately, as documented in:
https://github.com/IntersectMBO/cardano-ledger/issues/4571
Some Option fields in the script context certificates are going to
remain set to None, at least until the next Hard fork. There's a risk
that people permanently lock their funds if they expect deposits on
registration credentials to ever be `Some`.
So, we introduce a special type that emulate an `Option` that can only
ever be `None`. We call it `Never` and it is the first type of this
kind (i.e. with constructors indexes not starting at 0).
microproofs