Update snapshot.yml

Author: j5ik2o

.github/workflows/snapshot.yml

@@ -5,6 +5,9 @@ on:
       - CI
     types:
       - completed
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 jobs:
   snapshot:
     runs-on: ubuntu-latest