Bump GitHub Actions off deprecated Node 20 runtime

[apermo]

GitHub forces JavaScript actions off the Node 20 runtime starting 2026-06-16; Node 20 is removed from runners on 2026-09-16 (changelog). CI emits deprecation warnings for actions still pinned to their Node 20 majors.

Bumps each affected pin to the first major that ships on the Node 24 runtime. See the linked PR.

[github-actions]

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[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will not be closed automatically. If this issue is still relevant, please add a label or comment.