ci(deps): bump actions/download-artifact from 5 to 6 (#23)

Author: dependabot[bot]

.github/workflows/docker-build-push-multi-registry.yml

@@ -155,7 +155,7 @@ jobs:
       - build
     steps:
       - name: Download digests
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           path: ${{ runner.temp }}/digests
           pattern: digests-${{ inputs.build-digest-key }}-*