Merge pull request #158 from pytest-dev/cancel_old_pr_runs

cancel old pr runs on new push

Author: altendky

.github/workflows/ci.yml

@@ -13,6 +13,10 @@ on:
     # Daily at 05:47
     - cron: '47 5 * * *'
 
+concurrency:
+  group: ${{ github.ref }}-${{ github.workflow }}-${{ github.event_name }}-${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) && github.sha || '' }}
+  cancel-in-progress: true
+
 env:
   PIP_NO_PYTHON_VERSION_WARNING: 1