Generate digital attestations for PyPI (PEP 740) (#225)

Author: hugovk

.github/workflows/deploy.yml

@@ -59,6 +59,7 @@ jobs:
       - name: Upload package to Test PyPI
         uses: pypa/gh-action-pypi-publish@release/v1
         with:
+          attestations: true
           repository-url: https://test.pypi.org/legacy/
 
   # Upload to real PyPI on GitHub Releases.
@@ -88,3 +89,5 @@ jobs:
 
       - name: Upload package to PyPI
         uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          attestations: true