How do concurrency groups work, and how do you configure a workflow to automatically cancel in-progress runs when a new commit is pushed?

Concurrency groups allow restricting execution to only one job or workflow run at a time per group (e.g., per branch or per environment):

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

Setting cancel-in-progress: true automatically terminates active, older builds if a new push triggers a newer build, saving runner minutes.