fix(ci): add missing runs-on to PyPI publish workflow (#413)

Author: hf-kklein

.github/workflows/python-publish.yml

@@ -13,6 +13,7 @@ on:
 
 jobs:
    tests:
+     runs-on: ubuntu-latest
      if: startsWith(github.ref, 'refs/tags/v')
      steps:
        - uses: actions/checkout@v5