Conformance tests should cover all of language and protocol versions

Current the conformance test suite only covers the latest semantics variant, which is a certain specific combination of the language and protocol versions (at the time of writing it's PlutusV3 and Conway or later). We should cover all combinations that affect the behavior of program (which is currently controlled by the semantics variant, i.e. we should cover all semantics variants with the current structure of the builtins machinery).