Cancel previous workflows for PRs and branches (#2800)

.github/workflows/ci.yml

@@ -9,6 +9,10 @@ on:
 permissions:
   contents: read
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   ci:
     name: ${{ matrix.name }}