devops: cancel previous CI runs

Author: mxschmitt

.github/workflows/ci.yml

@@ -10,6 +10,12 @@ on:
       - main
       - release-*
 
+concurrency:
+  # For pull requests, cancel all currently-running jobs for this workflow
+  # https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#concurrency
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   infra:
     name: Lint