🧪🐛 Fix post-publish job permissions @ CI/CD

Declaring permissions explicitly takes away all the unlisted ones.
This patch fixes `git push` in the post-publish job by declaring
`contents: write` in it.

.github/workflows/ci-cd.yml

@@ -1239,6 +1239,7 @@ jobs:
       pull_request_url: ${{ steps.pr.outputs.pull_request_url }}
 
     permissions:
+      contents: write  # Mandatory for `git push` to work
       pull-requests: write
 
     steps: