Fix a bug in GHA due to unclear docs

One thing is documenting the event payloads, another is documenting
the event types, etc.

The end result is that this is a highly non-obvious string which we'll
have to guess until we get it right. And because it's a release-only
activity, the best way would be to take some dedicated testing time.
Since it's non-urgent, just fiddle with it here for now and revisit
later.

.github/workflows/publish_to_pypi.yaml

@@ -57,4 +57,4 @@ jobs:
         env:
           GH_TOKEN: ${{ github.token }}
           GH_REPO: ${{ github.repository }}
-        run: gh release upload "${{ github.release }}" dist/*.tgz
+        run: gh release upload "${{ github.event.release.name }}" dist/*.tgz