Update sigstore/gh-action-sigstore-python action to v3.4.0

Author: renovate[bot]

.github/workflows/publish.yaml

@@ -58,7 +58,7 @@ jobs:
           name: Packages
           path: dist
       - name: Sign the dists with Sigstore
-        uses: sigstore/gh-action-sigstore-python@f514d46b907ebcd5bedc05145c03b69c1edd8b46 # v3.0.0
+        uses: sigstore/gh-action-sigstore-python@5b79a39c381910c090341a2c9b0bf022c8b387e1 # v3.4.0
         with:
           inputs: >-
             ./dist/*.tar.gz