[bitnami/charts] review and improve workflow permissions (#16908)

Signed-off-by: Fran Mulero <fmulero@vmware.com>

.github/workflows/comments.yml

@@ -4,9 +4,10 @@ on:
     types:
       - created
 permissions:
+  contents: read
   repository-projects: write
-  issues: write
-  pull-requests: write
+  issues: read
+  pull_requests: read
 # Avoid concurrency over the same issue
 concurrency:
   group: card-movement-${{ github.event.issue.number }}