Should empty sub package be allowed

[justinvreeland]

Looks like exim has an empty subpackage entry. I was a bit surprised melange or the linter didn't throw an error for that.

wolfi-dev/os#32155

~/src/wolfi-MAIN main ≡ ⇣
❯ grep -C 4 subpackages exim.yaml
      mkdir -p "${{targets.destdir}}"/usr/lib/${{package.name}}

  - uses: strip

subpackages:

test:
  environment:
    contents: