Update sigstore/cosign-installer action to v3.8.1

Author: renovate[bot]

.github/workflows/build.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@e1523de7571e31dbe865fd2e80c5c7c23ae71eb4 # v3.4.0
+        uses: sigstore/cosign-installer@d7d6bc7722e3daa8354c50bcb52f4837da5e9b6a # v3.8.1
         with:
           cosign-release: 'v2.1.1'