Upgrade sigstore

Author: tovrstra

.github/workflows/release.yaml

@@ -77,7 +77,7 @@ jobs:
         name: python-package-distributions
         path: dist/
     - name: Sign the dists with Sigstore
-      uses: sigstore/gh-action-sigstore-python@v2.1.1
+      uses: sigstore/gh-action-sigstore-python@v3
       with:
         inputs: >-
           ./dist/*.tar.gz