tests(action): add test for scan-docker image action

Co-Authored-by: saisatishkarra <[email protected]>

.github/workflows/test.yml

@@ -0,0 +1,27 @@
+name: Test Shared Actions
+
+on:
+  pull_request:
+    branches:
+    - main
+  push:
+    branches:
+    - main
+
+jobs:
+  test-scan-docker-image:
+    name: Test Scan Docker Image
+    runs-on: ubuntu-22.04
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Login to DockerHub
+      if: success()
+      uses: docker/login-action@v2
+      with:
+        username: ${{ secrets.GHA_DOCKERHUB_PULL_USER }}
+        password: ${{ secrets.GHA_KONG_ORG_DOCKERHUB_PUBLIC_TOKEN }}
+
+    - uses: ./security-actions/scan-docker-image
+      with:
+        image: kong/kong-gateway-dev:latest # no particular reason for the choice of image or tag, just an image for tests