create scale down job

.github/workflows/scale-down.yml

@@ -0,0 +1,37 @@
+name: Scale down workers
+
+on:
+  workflow_dispatch:
+
+jobs:
+  test:
+    name: Scale
+    runs-on: ubuntu-latest
+    permissions:
+      contents: 'read'
+      id-token: 'write'
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Authenticate to Google Cloud
+        id: auth
+        uses: google-github-actions/auth@v2
+        with:
+          project_id: ${{ secrets.GCP_PROJECT_ID }}
+          workload_identity_provider: ${{ secrets.GCP_WORKLOAD_IDENTITY_ID }}
+          service_account: ${{ secrets.GCP_SERVICE_ACCOUNT }}
+
+      - name: Set up Google Cloud SDK
+        uses: google-github-actions/setup-gcloud@v1
+
+      - name: Get GKE credentials
+        id: 'get-credentials'
+        uses: 'google-github-actions/get-gke-credentials@v2'
+        with:
+          cluster_name: 'immutable-prod'
+          location: 'us-central1'
+
+      - name: Run benchmark script
+        run: >
+          kubectl scale --replicas=0 deployment/zero-bin-worker -n zkevm