Zig moves to drop bundled wasi-libc in 0.18.0

Sources: primary, discussion
Summary: A pull request on the Zig repository at Codeberg removes the bundled wasi-libc and is milestoned for 0.18.0. It is open and approved by andrewrk, and not merged. Zig 0.17.0 still ships wasi-libc.
Why it matters: Anyone targeting wasm32-wasi through Zig gets one more release on the current path, because the pull request is milestoned for 0.18.0 and 0.17.0 still ships wasi-libc.
Follow-up: Track whether the pull request merges before the 0.18.0 release.