CI/GH actions: update create-or-update-comment to v5

Author: dannywillems

.github/workflows/check-ocaml-refs.yaml

@@ -115,7 +115,7 @@ jobs:
 
       - name: Post PR comment with validation results
         if: github.event_name == 'pull_request'
-        uses: peter-evans/create-or-update-comment@v4
+        uses: peter-evans/create-or-update-comment@v5
         with:
           comment-id: ${{ steps.find-comment.outputs.comment-id }}
           issue-number: ${{ github.event.pull_request.number }}