Concurrent operations and Windows refinements mark Rustup 1.29.1 update

Rustup 1.29.1 introduces operational refinements for Rust's installer manager, focusing on performance optimizations and deprecated behaviors. Key updates include parallel update checks during `rustup update` and concurrent component installation with `rustup component add`, improving efficiency for multi-component workflows. The release discourages implicit toolchain installation in `rustup-init`, now triggering warnings where unnecessary, and fixes installation artifacts on cancellation. New functionality includes local HTTP documentation serving via `rustup doc --serve`, aiding containerized environments, while Windows users must now explicitly force non-host toolchain installations with `--force-non-host` for i686 targets. The update resolves Windows installation failures in `rustup-init.sh` and formalizes support for `aarch64-pc-windows-gnullvm` hosts. Terminology shifts from "target triple" to "target tuple" appear internally without CLI-breaking changes. Users can update via `rustup self update` or during routine toolchain updates. The release notes caution temporary anti-malware scanner conflicts with rust-docs installations, typically resolving within weeks as vendors update signature databases. These incremental improvements maintain Rustup's role in streamlining Rust toolchain management while addressing edge cases in cross-platform environments.