ci: bump sigstore/gh-action-sigstore-python to V3.0.0

Author: lukasbehammer

.github/workflows/release.yaml

@@ -321,7 +321,7 @@ jobs:
           merge-multiple: true
 
       - name: Sign the dists with Sigstore
-        uses: sigstore/gh-action-sigstore-python@v2.1.1
+        uses: sigstore/gh-action-sigstore-python@v3.0.0
         with:
           inputs: >-
             ./dist/*.tar.gz