add permissions to Publish Gem GitHub Actions

Author: yas-okadatech

.github/workflows/publish-gem.yml

@@ -8,7 +8,10 @@ on:
 jobs:
   publish:
     runs-on: ubuntu-latest
-    
+    permissions:
+      packages: write
+      contents: read
+
     steps:
     - name: Checkout code
       uses: actions/checkout@v4