The v12.3.2 release run died in "Package pnpm-napi darwin-x64" because
Apple clang segfaulted while linking the httparse build script. Nothing
in the tree changed; the same Blacksmith image built v12.3.1 fine the
day before. Every other packaging job was cancelled and the release had
to wait for the run to finish before "re-run failed jobs" was possible.
Route the three release cross builds through a wrapper script that
retries up to three times. Cargo keeps the crates a failed attempt
finished, so a retry only redoes the crate that died.
The Windows legs of build-rust and build-pnpr now run the build step
under bash instead of the default pwsh, as the napi packaging job
already did on both Windows targets. The clang-cl environment for
win32-arm64 is exported through GITHUB_ENV and GITHUB_PATH, so it
reaches bash the same way.