Fix release workflow

https://github.com/ruby-go-gem/go-gem-wrapper/actions/runs/11642268067/job/32421673488

```
⚠️ GitHub release failed with status: 403
{"message":"Resource not accessible by integration","documentation_url":"https://docs.github.com/rest/releases/releases#create-a-release","status":"403"}
Skip retry — your GitHub token/PAT does not have the required permission to create a release
Error: Resource not accessible by integration - https://docs.github.com/rest/releases/releases#create-a-release
```

Author: sue445

.github/workflows/release.yml

@@ -5,6 +5,9 @@ on:
     tags:
       - "v*"
 
+permissions:
+  contents: write
+
 jobs:
   publish:
     runs-on: ubuntu-latest