add permissions for trusted publishing to workflow

[angelphanth]

from python packaging user guide:

  publish-to-pypi:
    name: >-
      Publish Python 🐍 distribution 📦 to PyPI
    if: startsWith(github.ref, 'refs/tags/')  # only publish to PyPI on tag pushes
    needs:
    - build
    runs-on: ubuntu-latest
    environment:
      name: pypi
      url: https://pypi.org/p/<package-name>  # Replace <package-name> with your PyPI project name
    permissions:
      id-token: write  # IMPORTANT: mandatory for trusted publishing