clang-include-cleaner is used in the iwyu.yaml github workflow (include- what-you-use). Add it to the frozen toolchain so it can be made part of the regular build process. The corresponding install command is removed from iwyu.yaml. Regenerated frozen toolchain with optimized clang from https://devpkg.scylladb.com/clang/clang-21.1.8-Fedora-43-aarch64.tar.gz https://devpkg.scylladb.com/clang/clang-21.1.8-Fedora-43-x86_64.tar.gz Closes scylladb/scylladb#28413