Fix release workflow

Add permissions for writing contents, packages, and ID tokens.

Author: kwkwan

.github/workflows/release.yml

@@ -14,6 +14,12 @@ on:
     secrets:
       rubygems-api-key:
         required: true
+
+permissions:
+  contents: write
+  packages: write
+  id-token: write
+
 jobs:
   release:
     uses: metanorma/ci/.github/workflows/rubygems-release.yml@main