Ensure github actions are pinned using SHA.

Author: thomas-e-alma

.github/workflows/aqua.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
       - name: Run Aqua scanner
         uses: docker://aquasec/aqua-scanner