chore: Set permissions for GitHub actions

Restrict the GitHub token permissions only to the required ones; this way, even if the attackers will succeed in compromising your workflow, they won’t be able to do much.

- Included permissions for the action. https://github.com/ossf/scorecard/blob/main/docs/checks.md#token-permissions

https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#permissions

https://docs.github.com/en/actions/using-jobs/assigning-permissions-to-jobs

[Keeping your GitHub Actions and workflows secure Part 1: Preventing pwn requests](https://securitylab.github.com/research/github-actions-preventing-pwn-requests/)

Signed-off-by: naveen <172697+naveensrinivasan@users.noreply.github.com>

.github/workflows/ci.yml

@@ -309,6 +309,9 @@ jobs:
           webhookUrl: ${{ secrets.DISCORD_WEBHOOK }}
 
   cleanup-prior-runs:
+    permissions:
+      actions: write  # for rokroskar/workflow-run-cleanup-action to obtain workflow name & cancel it
+      contents: read  # for rokroskar/workflow-run-cleanup-action to obtain branch
     runs-on: ubuntu-20.04
     steps:
     - name: Cleanup previous runs on this branch