Update sigstore/cosign-installer action to v3.9.1

Author: renovate[bot]

.github/workflows/docker-publish.yml

@@ -41,7 +41,7 @@ jobs:
       # https://github.com/sigstore/cosign-installer
       - name: Install cosign
         if: github.event_name != 'pull_request'
-        uses: sigstore/cosign-installer@3454372f43399081ed03b604cb2d021dabca52bb # v3.8.2
+        uses: sigstore/cosign-installer@398d4b0eeef1380460a10c8013a76f728fb906ac # v3.9.1
         with:
           cosign-release: 'v1.11.0'