use intermediate environment variables to avoid risks of script injection

Signed-off-by: Batuhan Apaydın <batuhan.apaydin@trendyol.com>

ci/docker-publish.yml

@@ -41,10 +41,9 @@ jobs:
       # https://github.com/sigstore/cosign-installer
       - name: Install cosign
         if: github.event_name != 'pull_request'
-        uses: sigstore/cosign-installer@f3c664df7af409cb4873aa5068053ba9d61a57b6 #v2.6.0
+        uses: sigstore/cosign-installer@03d0fecf172873164a163bbc64bed0f3bf114ed7 #v3.4.0
         with:
-          cosign-release: 'v1.13.1'
-
+          cosign-release: 'v2.0.2'
 
       # Workaround: https://github.com/docker/build-push-action/issues/461
       - name: Setup Docker buildx
@@ -90,7 +89,9 @@ jobs:
       - name: Sign the published Docker image
         if: ${{ github.event_name != 'pull_request' }}
         env:
-          COSIGN_EXPERIMENTAL: "true"
+          # https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-an-intermediate-environment-variable
+          TAGS: ${{ steps.meta.outputs.tags }}
+          DIGEST: ${{ steps.build-and-push.outputs.digest }}
         # This step uses the identity token to provision an ephemeral certificate
         # against the sigstore community Fulcio instance.
-        run: echo "${{ steps.meta.outputs.tags }}" | xargs -I {} cosign sign {}@${{ steps.build-and-push.outputs.digest }}
+        run: echo "${TAGS}" | xargs -I {} cosign sign --yes {}@${DIGEST}