Three changes to the build-windows job:
1. CARGO_REGISTRIES_CRATES_IO_PROTOCOL=sparse — uses lightweight HTTPS
per-crate fetching instead of a full git clone of the crates.io index.
The git clone path triggers an SSL connection reset ([curl 35]) on
Windows Schannel in this runner environment.
2. CARGO_HTTP_MULTIPLEXING=false — disables HTTP/2 ALPN negotiation which
is another common source of Schannel SSL resets on Windows.
3. CARGO_NET_RETRY=5 — retry transient network errors up to 5 times before
failing the build.
4. Add Swatinem/rust-cache for Windows (mirrors the Linux job) — after a
successful build, compiled crates are cached so subsequent runs skip the
crates.io download entirely.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>