#2010 ci: cancel superseded PR runs of the test, Rust and install workflows

test-install.yml, rust-ci.yml and test-build.yml had no concurrency group. A new push to a PR left the previous commit's runs queued, taking runner slots the new commit needed. Today a superseded Test Install Script run for #2009 sat queued behind 16 others.

Each now has:

concurrency:
  group: ${{ github.workflow }}-${{ github.event_name == 'pull_request' && format('pr-{0}', github.event.pull_request.number) || github.sha }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

• PRs share one group per PR, so a new push cancels the earlier run.
• Everything else (pushes to main, manual runs) gets a group per commit, so nothing is cancelled. A shared group isn't enough here: GitHub still drops a pending run when a newer one queues in the same group, even with cancel-in-progress: false.

Release, merge, manual and reusable (workflow_call) workflows are unchanged. actionlint is clean. CI-only, so no changelog entry.

🤖 Generated with Claude Code

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Agent Relay sessions

• claude session 5a4f854b · opened via gh pr create · last active 2026-10-28