Have publishing workflow generate notes for GitHub release automatically (#284) [skip ci]

Author: stefmolin

.github/workflows/pypi-publish.yml

@@ -82,7 +82,7 @@ jobs:
         gh release create
         '${{ github.ref_name }}'
         --repo '${{ github.repository }}'
-        --notes ""
+        --generate-notes
     - name: Upload artifact signatures to GitHub Release
       env:
         GITHUB_TOKEN: ${{ github.token }}