Remove deferred builtin applications from the specification

[kwxm]

Fixes https://github.com/IntersectMBO/plutus-private/issues/1685.

New builtins caseList and caseData were added to UPLC in this PR in October 2024, but then we decided to extend UPLC's case costructor to case on built-in values instead and the builtins were removed again in this PR in July 2025.

Correspondingly I added caseList and caseData to the specification in this PR and removed them again in this PR. However, in the first PR I added "deferred applications" (HeadSpine in the implementation) which allowed a builtin to return an object of the form (v|v1,...,vn) (all of the v's values), which would then be evaluated as v applied to v1,..., vn by the CEK machine. When I removed caseList and caseData I left these deferred applications in the specification in case we needed them again later. However I'm now adding the new form of casing to the specification and that needs deferred applications of the form (e|e1, ..., en), where the e's are expressions, not values, and it's just confusing to keep the old deferred applications. I'm removing them in this PR separately from adding the new ones so that we can see what was removed in case we ever need it again.

I've added a rendered version of the PDF below. That may not be very helpful though: it's difficult to tell whether removing a bunch of stuff leaves the remainder of the specification in a sensible state (I think it does, but I could have missed something).

plutus-core-specification.pdf

[ana-pantilie]

I think this looks good, but I am not that familiar with the part of the spec that got removed, so I might also have missed something.

[basetunnel]

I have wondered before why the sequence of values was there in the spec. So caseData and caseList were never released on-chain then? Looks good.

[kwxm]

So caseData and caseList were never released on-chain then?

Correct. We put them in then took them back out.