fix: create releases as draft to allow asset uploads

The release must be created as draft initially, otherwise it's
published immediately and becomes immutable before assets upload.

Users can manually publish after assets are uploaded, or we can
add a workflow_dispatch to publish programmatically.

.github/workflows/release.yml

@@ -180,7 +180,7 @@ jobs:
         uses: softprops/action-gh-release@v2
         with:
           files: all-releases/*
-          draft: false
+          draft: true
           prerelease: ${{ contains(github.ref, '-rc') || contains(github.ref, '-beta') || contains(github.ref, '-alpha') }}
           generate_release_notes: true
           fail_on_unmatched_files: true