ARM runner support

[contrast-jproberts]

I tried to run pypa/gh-action-pypi-publish@76f52bc884231f62b9a034ebfe128415bbaabdfc # v1.12.4 on an ARM runner and received the following error (slightly redacted with $ variable names):

/usr/bin/docker run --name ghcriopypaghactionpypipublish76f52bc884231f62b9a034ebfe128415bbaabdfc_9c7292 --label 8fd87f --workdir /github/workspace --rm -e "INPUT_USER" -e "INPUT_PASSWORD" -e "INPUT_REPOSITORY-URL" -e "INPUT_PACKAGES-DIR" -e "INPUT_VERIFY-METADATA" -e "INPUT_SKIP-EXISTING" -e "INPUT_VERBOSE" -e "INPUT_PRINT-HASH" -e "INPUT_ATTESTATIONS" -e "HOME" -e "GITHUB_JOB" -e "GITHUB_REF" -e "GITHUB_SHA" -e "GITHUB_REPOSITORY" -e "GITHUB_REPOSITORY_OWNER" -e "GITHUB_REPOSITORY_OWNER_ID" -e "GITHUB_RUN_ID" -e "GITHUB_RUN_NUMBER" -e "GITHUB_RETENTION_DAYS" -e "GITHUB_RUN_ATTEMPT" -e "GITHUB_REPOSITORY_ID" -e "GITHUB_ACTOR_ID" -e "GITHUB_ACTOR" -e "GITHUB_TRIGGERING_ACTOR" -e "GITHUB_WORKFLOW" -e "GITHUB_HEAD_REF" -e "GITHUB_BASE_REF" -e "GITHUB_EVENT_NAME" -e "GITHUB_SERVER_URL" -e "GITHUB_API_URL" -e "GITHUB_GRAPHQL_URL" -e "GITHUB_REF_NAME" -e "GITHUB_REF_PROTECTED" -e "GITHUB_REF_TYPE" -e "GITHUB_WORKFLOW_REF" -e "GITHUB_WORKFLOW_SHA" -e "GITHUB_WORKSPACE" -e "GITHUB_ACTION" -e "GITHUB_EVENT_PATH" -e "GITHUB_ACTION_REPOSITORY" -e "GITHUB_ACTION_REF" -e "GITHUB_PATH" -e "GITHUB_ENV" -e "GITHUB_STEP_SUMMARY" -e "GITHUB_STATE" -e "GITHUB_OUTPUT" -e "GITHUB_ACTION_PATH" -e "RUNNER_OS" -e "RUNNER_ARCH" -e "RUNNER_NAME" -e "RUNNER_ENVIRONMENT" -e "RUNNER_TOOL_CACHE" -e "RUNNER_TEMP" -e "RUNNER_WORKSPACE" -e "ACTIONS_RUNTIME_URL" -e "ACTIONS_RUNTIME_TOKEN" -e "ACTIONS_CACHE_URL" -e "ACTIONS_ID_TOKEN_REQUEST_URL" -e "ACTIONS_ID_TOKEN_REQUEST_TOKEN" -e "ACTIONS_RESULTS_URL" -e GITHUB_ACTIONS=true -e CI=true -v "/var/run/docker.sock":"/var/run/docker.sock" -v "/home/runner/work/_temp/_github_home":"/github/home" -v "/home/runner/work/_temp/_github_workflow":"/github/workflow" -v "/home/runner/work/_temp/_runner_file_commands":"/github/file_commands" -v "/home/runner/work/$REPO/$REPO":"/github/workspace" ghcr.io/pypa/gh-action-pypi-publish:76f52bc884231f62b9a034ebfe128415bbaabdfc
Unable to find image 'ghcr.io/pypa/gh-action-pypi-publish:76f52bc884231f62b9a034ebfe128415bbaabdfc' locally
76f52bc884231f62b9a034ebfe128415bbaabdfc: Pulling from pypa/gh-action-pypi-publish
d2eb42b4a5eb: Pulling fs layer
# ... lots of intermediate Docker steps, omitted for brevity
4f4fb[70](https://github.com/$ORG/$REPO/actions/runs/14084165078/job/39444126058#step:3:76)0ef54: Pull complete
Digest: sha256:95f6a263932ad985f1b29df33a1748fddb8b92b46b7c95a2a3b3c6c7506096a3
Status: Downloaded newer image for ghcr.io/pypa/gh-action-pypi-publish:76f52bc884231f62b9a034ebfe128415bbaabdfc
WARNING: The requested image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested
exec /app/twine-upload.sh: exec format error

I don't see any issues, pull requests, or discussions clarifying support for using this action on ARM runners, so I wanted to start the discussion.

I've been migrating all jobs for a work project to use ARM larger runners because of the reduced cost. The publish step in our deployment workflow uses this action, and it isn't run often enough to optimize. Still, it would be simpler if as many of our jobs used the same runner as possible, and most jobs would be faster and cheaper to run on ARM larger runners.

GitHub hosted ARM runners are also currently in public preview: https://github.blog/changelog/2025-01-16-linux-arm64-hosted-runners-now-available-for-free-in-public-repositories-public-preview/ . With GitHub making it easier to use ARM runners, there could be more interest in ARM support for actions in the future.

In the meantime, I'll continue to use ubuntu-latest. I don't have a good estimate for how much effort ARM support requires. My hope is that this discussion can aggregate use cases for support, and to document the support decision.