ci: add strict GITHUB_TOKEN permissions (#76)

Author: carlosala

.github/workflows/publish.yml

@@ -9,6 +9,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+permissions:
+  contents: read
+
 jobs:
   publish:
     runs-on: ubuntu-latest