ci: add snyk scanning

adding snyk github action to
run when a PR is merged to the release
branch or when a new release is done.
Run snyk weekly on the devel branch.
This will help us to track the security
scanning results and fix if anything is
required and also it serves as a placeholder
for security scanning result for a while.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

.github/workflows/snyk.yaml

@@ -0,0 +1,30 @@
+---
+name: Security scanning
+# yamllint disable-line rule:truthy
+on:
+  schedule:
+    # Run weekly on Monday
+    - cron: '0 0 * * 1'
+  push:
+    tags:
+      - v*
+    branches:
+      - release-*
+
+permissions:
+  contents: read
+
+jobs:
+  security:
+    if: github.repository == 'ceph/ceph-csi'
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: run Snyk to check for code vulnerabilities
+        uses: snyk/actions/golang@master
+        env:
+          SNYK_TOKEN: ${{ secrets.SNYK_TOKEN }}