fix: workflow permission to upload trivy sarif report (#7234)

Trivy scan result upload to GitHub fails due to permission issue. Added permission security-events=write to the workflow file as a fix. Since workflow permission explicitly defined, it requires contents=read explicity set as well

Signed-off-by: Chaminda Divitotawela <[email protected]>

.github/workflows/container-security-scan.yml

@@ -14,6 +14,9 @@ on:
 jobs:
   scan-sarif:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      security-events: write
 
     steps:
       - name: Checkout