Update publish workflow to remove attestations (#16)

Author: thomas-bc

.github/workflows/publish.yml

@@ -29,5 +29,7 @@ jobs:
         uses: pypa/gh-action-pypi-publish@release/v1
         with:
           repository-url: https://test.pypi.org/legacy/
+      - name: Clean-Up Attestations
+        run: rm dist/*.attestation
       - name: Publish distributions to PyPI
         uses: pypa/gh-action-pypi-publish@release/v1