ci: build aarch64 and armv7l wheels on native ARM runners

[bdraco]

What do these changes do?

Move the aarch64 and armv7l legs of the odd-arch wheel matrix off the
x86_64 QEMU path and onto GitHub's public ubuntu-24.04-arm hosted
runner. aarch64 now builds natively with no emulation. armv7l still
gets docker/setup-qemu-action so binfmt registers a 32-bit ARM
handler whether or not the host kernel ships CONFIG_COMPAT; even
under emulation, running on an aarch64 host is far cheaper than the
previous aarch64-on-x86_64 layout.

ppc64le, s390x, and riscv64 keep the ubuntu-latest + QEMU setup
since there are no native GH-hosted runners for those.

The matrix gains an include: block that overrides runner-vm-os
and a native-arch flag per arch; the job-level qemu and
runner-vm-os expressions fall back to the previous behaviour for
the unmodified arches.

Ported from the equivalent yarl change in aio-libs/yarl#1724.

Are there changes in behavior for the user?

No. Wheels are still built for the same architectures and tags; only
the host that builds them changes. Release CI time on the aarch64
leg should drop from roughly 40 minutes to a few minutes.

Is it a substantial burden for the maintainers to support this?

No. ubuntu-24.04-arm is GA on public repositories; the
windows-11-arm precedent already in this workflow has the same
shape, and the reusable workflow's qemu / runner-vm-os inputs
stay unchanged.

Related issue number

No tracking issue; ported from aio-libs/yarl#1724.

Checklist

• I think the code is well written
• Unit tests for the changes exist - N/A (CI-only change, exercised by the next release run)
• Documentation reflects the changes - N/A
• If you provide code modification, please add yourself to CONTRIBUTORS.txt - already listed
• Add a new news fragment into the CHANGES/ folder

Agent run details (optional, for reviewers)

Drafted with Claude Code (claude-opus-4-7); reviewed by @bdraco.

Local validation:

• pre-commit run --files .github/workflows/ci-cd.yml CHANGES/1354.contrib.rst docs/spelling_wordlist.txt (yamllint, Validate GitHub Workflows, Check GitHub Workflows set timeout-minutes, changelog :user: role check) all passed.
• python -c "yaml.safe_load(open('.github/workflows/ci-cd.yml'))" confirms the matrix include: shape and that the ${{ ! matrix.native-arch }} / ${{ matrix.runner-vm-os || 'ubuntu-latest' }} expressions parse cleanly.
• make doc-spelling reports only 5 pre-existing misspellings in CHANGES.rst that are also present on master; the fragment introduced aarch only, added to docs/spelling_wordlist.txt.

Not validated locally: actual native-ARM cibuildwheel run. The runner
label and matrix wiring look correct, but the real proof is the first
CI run on this branch.

[codspeed-hq]

Merging this PR will not alter performance

✅ 242 untouched benchmarks

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_{Comparing bdraco:ci/native-arm-wheels (c4ce09d) with master (6696a1c)}