ci: Opt-in for Secret-scanner workflow (#696)

.github/workflows/secret-scanner.yml

@@ -0,0 +1,15 @@
+# Secret-scanner workflow from Arista Networks.
+on:
+  pull_request:
+    types: [synchronize]
+  push:
+    branches:
+      - main
+name: Secret Scanner (go/secret-scanner)
+jobs:
+  scan_secret:
+    name: Scan incoming changes
+    runs-on: ubuntu-latest
+    steps:
+      - name: Run scanner
+        uses: aristanetworks/secret-scanner-service@main