ci: cancel previous CI run for PR or branch

.github/workflows/ci.yml

@@ -17,6 +17,10 @@ on:
         required: false
         type: string
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 permissions:
   pull-requests: write