Allow build-tags to run on forks

Allow build-tags to run on forks

build-tags uses: PowerDNS/pdns/.github/workflows/build-packages.yml@master
As of f107ec62467b8779db9bbdb175721ef232ed52e5, that workflow requires:

    permissions:
      actions: read   # To read the workflow path.
      id-token: write # To sign the provenance.
      contents: write # To be able to upload assets as release artifacts

Per https://docs.github.com/en/actions/using-workflows/reusing-workflows
in order for this to work, the calling job (in build-tags) needs to
have the maximum required permissions in order for the calling workflow
to be run.