Prefer RequiredPassInfoMixin (#3913)
In LLVM 23, {Optional,Required}PassInfoMixin became preferred for
creating passes instead of raw PassInfoMixin with isRequired. In LLVM
24, PassInfoMixin will be moved to a detail namespace, causing
compilation failures.
Original commit:
https://github.com/KhronosGroup/SPIRV-LLVM-Translator/commit/25ec4c4cb760694
