fix: add packages:write permission to release workflows

The automatic GITHUB_TOKEN needs explicit package scope for
uploading to the Gitea Generic Package Registry.

.gitea/workflows/release-nightly.yml

@@ -10,6 +10,10 @@ env:
   GONOSUMCHECK: git.lethalbits.com/*
   GOINSECURE: git.lethalbits.com/*
 
+permissions:
+  contents: read
+  packages: write
+
 jobs:
   publish-nightly:
     runs-on: ubuntu-latest