Upgrade to hugr-llvm 0.26+, with llvm21-1. Main challenge is the removal of opaque pointers, see the [hugr-llvm PR](https://github.com/Quantinuum/hugr/pull/2901).
Upgrade to hugr-llvm 0.26+, with llvm21-1. Main challenge is the removal of opaque pointers, see the hugr-llvm PR.