Support Windows ARM Runners

[maennchen]

GitHub added Windows Arm64 hosted runners:

https://docs.github.com/en/actions/using-github-hosted-runners/using-github-hosted-runners/about-github-hosted-runners#standard-github-hosted-runners-for-public-repositories

The windows-11-arm image unfortunately comes without rustup installed, resulting in the following error:

https://github.com/maennchen/gleam/actions/runs/14616757309/job/41006654440

Run actions-rust-lang/setup-rust-toolchain@v1
  with:
    toolchain: stable
    target: aarch64-pc-windows-msvc
    cache-key: v1-aarch64-pc-windows-msvc
    cache: true
    cache-on-failure: true
    cache-bin: true
    matcher: true
    rustflags: -D warnings
    override: true
  env:
    CARGO_TERM_COLOR: always
    RUSTFLAGS: -D warnings
Run : construct rustup command line
  : construct rustup command line
  echo "targets=$(for t in ${targets//,/ }; do echo -n ' --target' $t; done)" >> $GITHUB_OUTPUT
  echo "components=$(for c in ${components//,/ }; do echo -n ' --component' $c; done)" >> $GITHUB_OUTPUT
  echo "downgrade=" >> $GITHUB_OUTPUT
  shell: C:\Program Files\Git\bin\bash.EXE --noprofile --norc -e -o pipefail {0}
  env:
    CARGO_TERM_COLOR: always
    RUSTFLAGS: -D warnings
    targets: aarch64-pc-windows-msvc
    components: 
  
Run if [[ ! -v CARGO_INCREMENTAL ]]; then
Run echo "::add-matcher::C:\a\_actions\actions-rust-lang\setup-rust-toolchain\v1/rust.json"
  
Run if [[ -z "$toolchain" && ( -f "rust-toolchain" || -f "rust-toolchain.toml" ) ]]
C:\a\_temp\6dbba988-4564-4c[39](https://github.com/maennchen/gleam/actions/runs/14616757309/job/41006654440#step:4:43)-89e8-552e03bf3b06.sh: line 19: rustup: command not found
Error: Process completed with exit code 127.

The action seems to skip install for Windows in general (same issue as #45):

setup-rust-toolchain/action.yml

Lines 132 to 139 in 9399c7b

	- name: Install rustup, if needed
	if: runner.os != 'Windows'
	shell: bash
	run: |
	if ! command -v rustup &> /dev/null ; then
	curl --proto '=https' --tlsv1.2 --retry 10 --retry-connrefused -fsSL "https://sh.rustup.rs" | sh -s -- --default-toolchain none -y
	echo "${CARGO_HOME:-$HOME/.cargo}/bin" >> $GITHUB_PATH
	fi

It would be nice to support Windows rustup installation and therefore all GH hosted runners.

[maennchen]

Btw, this is how rustup is installed on the X64 runners. We can probably copy from there for the installation steps:
https://github.com/actions/runner-images/blob/fbc3fb1d0f7629374c71bbbf553480dd7b6b95a5/images/windows/scripts/build/Install-Rust.ps1