chore: Update cosign

Author: dploeger

.github/workflows/docker-publish.yml

@@ -36,7 +36,7 @@ jobs:
         if: github.event_name != 'pull_request'
         uses: sigstore/cosign-installer@d6a3abf1bdea83574e28d40543793018b6035605
         with:
-          cosign-release: 'v1.7.1'
+          cosign-release: 'v1.9.0'
 
 
       # Workaround: https://github.com/docker/build-push-action/issues/461