Update sigstore/gh-action-sigstore-python digest to cf13514

Author: renovate[bot]

.github/workflows/sign-release.yml

@@ -39,6 +39,6 @@ jobs:
           python -m pip install .
 
       - name: Sign Script with Sigstore
-        uses: sigstore/gh-action-sigstore-python@15ce42889ff1d65509841d7c63480f64affe3a64
+        uses: sigstore/gh-action-sigstore-python@cf13514655797e228415f3190222e4f09c72e213
         with:
           release-signing-artifacts: true