Add upload.pypi.org to allowed domains in publish job (#321)

Author: btschwertfeger

.github/workflows/_pypi_publish.yaml

@@ -34,6 +34,7 @@ jobs:
           allowed-endpoints: >
             ghcr.io
             pypi.org
+            upload.pypi.org
             tuf-repo-cdn.sigstore.dev
             fulcio.sigstore.dev
             rekor.sigstore.dev