Bump stumpylog/image-cleaner-action from 0.5.0 to 0.6.0 (#207)

Author: dependabot[bot]

.github/workflows/image-cleanup.yml

@@ -28,7 +28,7 @@ jobs:
           .github/workflows/scripts/delete-untagged-amazon-public-ecr-images.sh
 
       - name: Delete untagged NGINX Unprivileged Docker images on the GitHub Container Registry
-        uses: stumpylog/image-cleaner-action/untagged@9255a1b3b8ca44b3e5887e2168155223b277ca1d # v0.5.0
+        uses: stumpylog/image-cleaner-action/untagged@0c9e57eef74b24c7b41f98f73dcb404eb58b2fab # v0.6.0
         with:
           is_org: true
           owner: nginxinc